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Light‐emitting diodes (LEDs) based on perovskite quantum dots (QDs), abbreviated as P‐QLEDs have been regarded as significantly crucial emitters for lighting and displays. Efficient and stable P‐QLEDs still lack ideal electron transport materials (ETM), which could efficiently block hole, transport electron, reduce interface non‐radiative recombination and possess high thermal stability. Here, we report 2,4,6‐Tris(3′‐(pyridine‐3‐yl) biphenyl‐3‐yl)‐1,3,5‐triazine (TmPPPyTz, 3P) with strong electron‐withdrawing moieties of pyridine and triazine to modulate the performance of P‐QLEDs. Compared with commonly used 1,3,5‐Tris(1‐phenyl‐1H‐benzimidazol‐2‐yl)benzene (TPBi), the pyridine in 3P have a strong interaction with perovskites, which can effectively suppress the interface non‐radiative recombination caused by the Pb2+ defects on the surface of QDs. In addition, 3P have deep highest occupied molecular orbital (HOMO) (enhancing hole‐blocking properties), matched lowest unoccupied molecular orbital (LUMO) and excellent electron mobility (enhancing electron transport properties), realizing the carrier balance and maximizing the exciton recombination. Furthermore, high thermal resistance of 3P obviously improves the stability of QDs under variable temperature, continuous UV illumination, and electric field excitation. Resultantly, the P‐QLEDs using the 3P as ETM achieved an outstanding performance with a champion EQE of 30.2 % and an operational lifetime T50 of 3220 hours at an initial luminance of 100 cd m−2, which is 151 % and about 11‐fold improvement compared to control devices (EQE=20 %, T50=297 hours), respectively. These results provide a new concept for constructing the efficient and stable P‐QLEDs from the perspective of selective ETM. [ABSTRACT FROM AUTHOR]

As a critical component of electrostatic capacitors, the polymer dielectric directly affects the performance of the capacitor. In this work, Polycarbonate (PC)/Polyvinylidene fluoride (PVDF) asymmetric bilayer polymer dielectrics were prepared, and the influence of different polymer materials' barrier characteristics on various electrical properties of composite dielectrics was studied by changing the direction of applied electric fields. Research has found that the dielectric constant of a composite dielectric is between PVDF and PC (approximately 4.8 at 10 Hz) and is independent of the relative position of PVDF and PC in the dielectric. However, the relative position of PC and PVDF has a significant impact on the energy-storage characteristics of composite dielectrics. When PVDF comes into contact with the negative electrode, even though PC has a higher hole barrier, the composite dielectric can only withstand a maximum electric-field strength of 400 MV/m, which is much lower than the maximum electric-field strength that pure PC can withstand (520 MV/m), and it only achieves an energy-storage density of 3.7 J/cm3. When the PC comes into contact with the negative electrode, the high electron barrier of the PC effectively suppresses the injection of electrons at the electrode. It can withstand the same electric-field strength as PC (520 MV/m), achieving an energy-storage density of 5.48 J/cm3, which is 1.46 times that of pure PC and 1.64 times that of PVDF. This experiment effectively combined the advantages of PC and PVDF by utilizing the electron/hole barrier of polymer materials to obtain a fully organic dielectric with excellent energy-storage performance. [ABSTRACT FROM AUTHOR]

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Metal halide perovskite semiconductors have demonstrated remarkable performance in light‐emitting‐diode applications in recent years. However, their potential application in other emerging optoelectronic devices, such as light‐emitting field‐effect transistors (LEFETs) is impeded by poor luminous efficiency due to inefficient charge injection. Here, an n‐type MgZnInO (MIZO) as the channel layer is synthesized to achieve efficient electron injection in perovskite LEFETs. These findings indicate that the incorporation of Mg not only suppresses the generation of oxygen vacancies but also optimizes the energy level alignment. These synergistic effects reduce non‐radiative recombination and improve interfacial charge transport. Consequently, the MIZO‐based perovskite LEFETs exhibit an improvement in threshold voltage, subthreshold swing, and field‐effect mobility. The electroluminescence performance shows a peak external quantum efficiency (EQE) of 1.97% with a maximum brightness of 2.1 × 104 cd m−2, accompanied by low‐efficiency roll‐off (an EQE of 1.88% at the current density of 810 mA cm−2). To the best of the author's knowledge, this represents the best luminous efficiency reported for perovskite LEFETs to date. [ABSTRACT FROM AUTHOR]

Context: The new series of donor-π-acceptor dyes have been designed using pyridine derivatives as a donor group and thienothiophene as a π-spacer group, which were linked via 10 acceptor groups. The highest occupied molecular orbital energies range from − 6.177 to − 5.786 eV, whereas the lowest unoccupied molecular orbital energies range from − 2.181 to − 3.664 eV. A6 dye has smaller energy gap, lower hardness, higher electrophilicity index, and good photovoltaic performance than other sensitizers. The lowest dihedral angle is observed in A1, A2, A6, A7, and A8 which are appropriate for intramolecular charge transfer between the molecules. The A8 has higher light harvesting efficiency, which increases the photovoltaic efficiency of the designed dye. The A6, A7, and A8 dyes spend less time in the excited state, which means they emit photons more efficiently than other dyes. The interaction between donor to π-spacer (red line) parts of the dyes has the bonding interaction (positive), and π-spacer to acceptor (blue line) parts of the dyes have the bonding and antibonding (negative) behaviours. The dyes A5 and A9 have 305.79 and 357.71 times higher β0 values than urea (0.781 × 10−30 esu) molecules. The spectral properties of the A6 dye strongly affect the structural modification. Methods: The density functional theory (DFT) and time-dependent DFT (TD-DFT) approach B3LYP/6-311G (d,p) basic set were used to optimize the designed dyes. All the calculations are performed using Gauss view 6.0 and Gaussian 09 software. The density of state spectrum is plotted using Gauss sum 2.6. [ABSTRACT FROM AUTHOR]

Context: The world's energy and environmental requirements are changing due to rapid population growth and industrial growth, and solar cells can be used to meet these demands. Dye-sensitized solar cells (DSSCs) are solar cells in which energy conversion occurs via a process similar to photosynthesis in plants. DSSC development is still in its infancy. DSSCs can operate under cloudy conditions and indirect sunlight and have attracted considerable attention due to their low cost and high efficiency. We designed two metal-free TPA-based dyes (Dye2 and Dye3) based on the reference dye Mg207 (Dye1) by increasing the donor strength of the molecule, as such dyes have shown enhanced efficiency in DSSCs. Moreover, the triphenylamine (TPA) moiety has been demonstrated to be a good donor that prevents charge recombination. Intramolecular charge transfer (ICT) from the donor to acceptor moiety was found in the sensitizers, and electrons were promoted to the conduction band (CB) of the TiO2 semiconductor. The negative binding energy of the dye@TiO2 clusters indicated that dye adsorption on the semiconductor surface was stable. The double donor increased the electron injection and electronic coupling constants in Dye2 and Dye3, indicating that these newly designed dyes have superior charge injection capacity. Accordingly, the efficiencies of DSSCs with Dye2 and Dye3 were 9.77% and 9.62%, respectively, and substitution with the TPA unit at the -R1 and -R2 positions in Dye1 resulted in better power conversion compared to the parent compound (9.09%). Increased donor strength improved photovoltaic performance by increasing current density and light-harvesting efficiency. This is a good molecular design approach for preparing targeted donor- π -acceptor (D- π -A) organic dyes with high DSSC efficiency. Methods: To predict the charge transport and optoelectronic characteristics of the TPA dyes, quantum chemical calculations were carried out using Gaussian16. The ground-state (S0) optimized geometries of the sensitizers were computed by utilizing DFT at the B3LYP/6-31G** level. The absorption spectra (λ max) were computed by employing TD-DFT with various functionals (B3LYP, PBE1PBE, CAM-B3LYP, and BHandHLYP) in the gas and solvent (DCM) phases. Among the studied functionals, BHandHLYP was found to be best at successfully reproducing the experimental data. Thus, the absorption spectra of the newly designed dyes and dye@TiO2 were calculated at the BHandHLYP/6-31G** level. The dye@TiO2 cluster optimizations were carried out at the B3LYP/6-31G**(LANL2DZ) level. [ABSTRACT FROM AUTHOR]

We propose a technique for the wafer-level testing of the gate dielectrics of metal–insulator–semiconductor (MIS) devices by the high-field injection of electrons into the dielectric using a mode of increasing injection current density up to a set level. This method provides the capability to control a change in the charge state of the gate dielectric during all the testing. The proposed technique makes it possible to assess the integrity of the thin dielectric and at the same time to control the charge effects of its degradation. The method in particular can be used for manufacturing processes to control integrated circuits (ICs) based on MIS structures. In the paper, we propose an advanced algorithm of the Bounded J-Ramp testing of the gate dielectric and receive its approval when monitoring the quality of the gate dielectrics of production-manufactured MIS devices. We found that the maximum value of positive charge obtained when tested by the proposed method was a value close to that obtained when the charge was injected into the dielectric under a constant current with a Bounded J value despite large differences in the rate of degradation of the dielectric. [ABSTRACT FROM AUTHOR]

Inorganic perovskite quantum dots (QDs) have garnered significant attention due to their outstanding optical properties. However, perovskite quantum dot light‐emitting diodes (Pe‐QLEDs) still face challenges related to their fluorescence efficiency and electron injection. First, the electron transport layer (ETL) leads to severe non‐radiative recombination due to fluorescence quenching in CsPbI3 QDs. Second, there is an electron injection imbalance resulting from low electron injection efficiency, leading to reduced non‐radiative recombination and external quantum efficiency. To address these issues, this study introduces two interface layer materials with different electron affinities, 1,3,5‐Tris(3‐pyridyl‐3‐phenyl)benzene (TmPyPB) and 2,4,6‐Tris(3′‐(pyridine‐3‐yl)biphenyl‐3‐yl)‐1,3,5‐triazine (TmPPPyTz). These materials not only passivated defects on the surface of CsPbI3 QDs films but also effectively prevented the fluorescence quenching of CsPbI3 QDs by the PO‐T2T (ETL). TmPPPyTz, with a relatively lower LUMO energy level, further improved energy level matching, significantly enhancing electron injection efficiency. Ultimately, using interface engineering with the TmPPPyTz interface layer, the devices achieved an outstanding 25.80% champion‐level external quantum efficiency (EQE) for Pe‐QLEDs with only a sub‐bandgap voltage of 1.7 V and half‐life (T50) is 17.99 h at 100 nits. This research provided an effective method to enhance the performance of CsPbI3 Pe‐QLEDs, addressing long‐standing issues inhibiting their efficiency. [ABSTRACT FROM AUTHOR]

The crown leaves of pineapple possess a wealth of smooth and glossy silk medium-length fibers, primarily composed of cellulose and lignin, accompanied by constituents such as fats, waxes, pectin, uronic acid, anhydride, pentosan, color pigments, and inorganic substances. These fibers exhibit an anisotropic nature and are characterized by hydrogen bonding interactions, rendering them effective in conjunction with semiconductor oxide (TiO2) through their cellulosic fibrils. The dye extracted from Pineapple Crown Leaves (PCL) using ethanol was subjected to FTIR and UV–visible spectroscopy. The FTIR analysis revealed absorption peaks at 3268 cm−1 and 2922 cm−1, confirming the presence of –OH and –CH stretching attributed to the fibrils within the dye. UV–visible spectroscopy further demonstrated absorption within the visible region of the electromagnetic spectrum. Additionally, a photoluminescence study of the dye showcased emission within the visible range of the electromagnetic spectrum. Subsequently, a solar cell incorporating this dye underwent JV characterization, yielding an efficiency of 1.0034%, along with fill factor, open-circuit voltage, and short-circuit current density values of 0.40644, 0.7058 V, and 3.4906 mA/cm2, respectively. To gain deeper insights and facilitate optimization for large-scale installations, a simulation model utilizing PC1D was proposed to explore the influential parameters of the Dye-sensitized solar cell (DSSC). [ABSTRACT FROM AUTHOR]

A dye-sensitized solar cell (DSSC) has been fabricated with a photoanode made with silver-decorated reduced graphene oxide over the layer of TiO2 nanoparticle coated over the FTO substrate using the Doctor Blade method. Due to the excellent electrical conductivity of silver decorated reduced graphene oxide and high adsorption of dye molecules, the cell parameters are enhanced. Three different concentrations of Ag decorated rGO (0.1% wt, 0.2% wt, and 0.3% wt) have been considered for this study and are compared with pure TiO2-based DSSC. It is confirmed that the 0.1% wt concentration of TiO2-Ag decorated rGO has shown better performance than the other concentrations as well as the pure TiO2 photoanode. Natural dyes having chlorophyll pigment have been used as sensitizers, and graphene-based counter electrodes are incorporated in all solar cells. DSSC of 0.1% wt concentration of TiO2-Ag decorated rGO has given short circuit current density, open circuit voltage, fill factor, and power conversion efficiency of 3.768 mA/cm2, 0.6518 V, 0.566, and 1.39%, respectively. The higher the concentration of Ag decorated rGO with TiO2, the lower the electron injection into the semiconductor oxide with increased band gap energy. In this experiment, we found that 0.1% wt concentration of TiO2-Ag decorated rGO has given a short power conversion efficiency of 1.39%, respectively. [ABSTRACT FROM AUTHOR]

Abstract The crown leaves of pineapple possess a wealth of smooth and glossy silk medium-length fibers, primarily composed of cellulose and lignin, accompanied by constituents such as fats, waxes, pectin, uronic acid, anhydride, pentosan, color pigments, and inorganic substances. These fibers exhibit an anisotropic nature and are characterized by hydrogen bonding interactions, rendering them effective in conjunction with semiconductor oxide (TiO2) through their cellulosic fibrils. The dye extracted from Pineapple Crown Leaves (PCL) using ethanol was subjected to FTIR and UV–visible spectroscopy. The FTIR analysis revealed absorption peaks at 3268 cm−1 and 2922 cm−1, confirming the presence of –OH and –CH stretching attributed to the fibrils within the dye. UV–visible spectroscopy further demonstrated absorption within the visible region of the electromagnetic spectrum. Additionally, a photoluminescence study of the dye showcased emission within the visible range of the electromagnetic spectrum. Subsequently, a solar cell incorporating this dye underwent JV characterization, yielding an efficiency of 1.0034%, along with fill factor, open-circuit voltage, and short-circuit current density values of 0.40644, 0.7058 V, and 3.4906 mA/cm2, respectively. To gain deeper insights and facilitate optimization for large-scale installations, a simulation model utilizing PC1D was proposed to explore the influential parameters of the Dye-sensitized solar cell (DSSC).

Improving light-harvesting efficiency and suppressing interfacial charge recombination are of paramount importance to the development of Cu (II/I) redox shuttle-based dye-sensitized solar cells (DSSCs). Here, we present a rational molecular engineering on D-A-π-A organic sensitizers featuring with fluorenyl-substituted bulky donor (HY57, HY60, and HY61) for Cu (II/I) mediated DSSCs. By gradually enhancing conjugation and rigidity of the π-spacer and auxiliary acceptor moieties, the light-harvesting and electron-injection efficiencies can be simultaneously improved. The large size of fluorenyl-substituted arylamine donor together with abundant alkyl chains decorated on the molecular structures assist dense assembly of dye monolayer at surface of nanocrystalline TiO2, which largely suppress interfacial charge recombination losses. When applied in Cu (II/I) mediated DSSCs, the combination of an auxiliary acceptor of phenanthrene-fused-quinoxaline (PFQ) and a π-spacer of cyclopentadithiophene (CPDT) in dye HY61 results in a simultaneous enhancement in short-circuit current (JSC) and open-circuit voltage (VOC), thus improving the power conversion efficiency (PCE) from 7.3% for reference dye HY59 to 10.3% for HY61. This study demonstrates that rigid and fused building block is promising towards constructing highly efficient organic sensitizers.

As a critical component of electrostatic capacitors, the polymer dielectric directly affects the performance of the capacitor. In this work, Polycarbonate (PC)/Polyvinylidene fluoride (PVDF) asymmetric bilayer polymer dielectrics were prepared, and the influence of different polymer materials’ barrier characteristics on various electrical properties of composite dielectrics was studied by changing the direction of applied electric fields. Research has found that the dielectric constant of a composite dielectric is between PVDF and PC (approximately 4.8 at 10 Hz) and is independent of the relative position of PVDF and PC in the dielectric. However, the relative position of PC and PVDF has a significant impact on the energy-storage characteristics of composite dielectrics. When PVDF comes into contact with the negative electrode, even though PC has a higher hole barrier, the composite dielectric can only withstand a maximum electric-field strength of 400 MV/m, which is much lower than the maximum electric-field strength that pure PC can withstand (520 MV/m), and it only achieves an energy-storage density of 3.7 J/cm3. When the PC comes into contact with the negative electrode, the high electron barrier of the PC effectively suppresses the injection of electrons at the electrode. It can withstand the same electric-field strength as PC (520 MV/m), achieving an energy-storage density of 5.48 J/cm3, which is 1.46 times that of pure PC and 1.64 times that of PVDF. This experiment effectively combined the advantages of PC and PVDF by utilizing the electron/hole barrier of polymer materials to obtain a fully organic dielectric with excellent energy-storage performance.

The results of experimental studies of a discharge system based on a pulsed (200–400 μs, 5–25 Hz) high-current (5–30 A) planar magnetron discharge with a target diameter of 125 mm and additional electron injection from a vacuum arc discharge are presented. The electron injection into the magnetron discharge is carried out from the back of the sputtered target through the central aperture, which provides additional acceleration of the injected electrons in a cathode layer of the magnetron discharge and an increase in the energy efficiency of the discharge system. The mass-to-charge ion composition of the generated plasma has been studied in a range of operating pressure up to an extremely low level of 0.2 mTorr. The conditions to achieve a high fraction of target material ions in the magnetron plasma are defined, including those in the range of low operating pressure range, where the typical magnetron discharge is characterized by an increase of a working gas ion fraction, and transfers into a low-current form. [ABSTRACT FROM AUTHOR]

Improving light-harvesting efficiency and suppressing interfacial charge recombination are of paramount importance to the development of Cu (II/I) redox shuttle-based dye-sensitized solar cells (DSSCs). Here, we present a rational molecular engineering on D-π-p-π organic sensitizers featuring with fluorenyl-substituted bulky donor (HY57, HY60, and HY61) for Cu (II/I) mediated DSSCs. By gradually enhancing conjugation and rigidity of the p-spacer and auxiliary acceptor moieties, the light-harvesting and electron-injection efficiencies can be simultaneously improved. The large size of fluorenyl-substituted arylamine donor together with abundant alkyl chains decorated on the molecular structures assist dense assembly of dye monolayer at surface of nanocrystalline TiO2, which largely suppress interfacial charge recombination losses. When applied in Cu (II/I) mediated DSSCs, the combination of an auxiliary acceptor of phenanthrene-fused-quinoxaline (PFQ) and a p-spacer of cyclopentadithiophene (CPDT) in dye HY61 results in a simultaneous enhancement in short-circuit current (JSC) and open-circuit voltage (VOC), thus improving the power conversion efficiency (PCE) from 7.3% for reference dye HY59 to 10.3% for HY61. This study demonstrates that rigid and fused building block is promising towards constructing highly efficient organic sensitizers. [ABSTRACT FROM AUTHOR]

Whistler mode chorus waves appear either as a series of discrete elements (rising or falling tones) or as banded hiss‐like emissions in the dynamic spectrogram. Although the generation of rising‐tone chorus waves has been extensively studied, few studies have focused on the generation of hiss‐like emissions. In this paper, using the one‐dimensional (1‐D) general curvilinear particle‐in‐cell (gcPIC) simulation model, we have thoroughly studied the generation mechanisms of hiss‐like emissions. Based on the spectrogram, we first classify hiss‐like emissions into four types (I, II, III, and IV). We find that the type I hiss‐like waves are linearly excited by the anisotropic electrons, while other types are excited through the nonlinear process. For the type I waves, they do not undergo a frequency chirping process and have a relatively broadband spectrum. The high proportion of hot electrons or the large temperature anisotropy of hot electrons will decrease the threshold for nonlinear growth and cause the wave amplitudes to exceed the threshold, leading to the nonlinear generation of type II hiss‐like waves. The fresh hot electrons continually injected into the system with a large drift velocity significantly reduces the time interval between the rising tone elements to form a continuous spectrum, which are the type III waves. The intense and long‐lasting hiss‐like emissions, that is, type IV, which are the most frequently observed, should be generated due to the combined effect of the rapid injection and the high proportion of hot electrons (or the large temperature anisotropy). Our findings provide a comprehensive understanding of the generation of hiss‐like chorus waves in the Earth's magnetosphere. Plain Language Summary: Chorus waves are important electromagnetic waves in the inner magnetosphere, which typically appears as either hiss‐like emissions or discrete rising or falling tones. Although much effort has been spent on explaining the frequency chirping of chorus waves, the generation of hiss‐like emissions have long been neglected, which are actually the more common spectrogram than the discrete ones. Based on Van Allen Probes data, we first reveal that the hiss‐like emissions can be further divided into four types (I, II, III, and IV). Then, we utilize a one‐dimensional general curvilinear particle‐in‐cell (gcPIC)‐δf model to successfully reproduce the four types of hiss‐like emissions. We propose that the type I hiss‐like waves are linearly excited by the electrons with a temperature anisotropy, while other types undergo the nonlinear growth. The high proportion or large temperature anisotropy of hot electrons will cause the strong nonlinear growth, resulting in the generation of the type II hiss‐like waves. The type III waves depend on the continuous injection of energetic electrons caused by the azimuthal drift. Due to the combined effect of the rapid injection and intense nonlinear growth, the intense and long‐lasting hiss‐like emissions, that is, type IV, which are the most frequently observed, are generated. Our findings provide a deeper insight of the generation of hiss‐like chorus waves in the terrestrial magnetosphere. Key Points: A 1‐D general curvilinear particle‐in‐cell simulation model is used to study the generation mechanisms of hiss‐like emissionsBased on the spectrogram, the hiss‐like emissions are classified into four types (I, II, III, IV)The majority of hiss‐like chorus waves in the Earth's magnetosphere are generated through a nonlinear process [ABSTRACT FROM AUTHOR]

We propose a technique for the wafer-level testing of the gate dielectrics of metal–insulator–semiconductor (MIS) devices by the high-field injection of electrons into the dielectric using a mode of increasing injection current density up to a set level. This method provides the capability to control a change in the charge state of the gate dielectric during all the testing. The proposed technique makes it possible to assess the integrity of the thin dielectric and at the same time to control the charge effects of its degradation. The method in particular can be used for manufacturing processes to control integrated circuits (ICs) based on MIS structures. In the paper, we propose an advanced algorithm of the Bounded J-Ramp testing of the gate dielectric and receive its approval when monitoring the quality of the gate dielectrics of production-manufactured MIS devices. We found that the maximum value of positive charge obtained when tested by the proposed method was a value close to that obtained when the charge was injected into the dielectric under a constant current with a Bounded J value despite large differences in the rate of degradation of the dielectric.

Electron cyclotron harmonic (ECH) waves along with whistler mode waves are suggested to be responsible for causing the persistent diffuse aurora in Jupiter. In this work, for the first time we systematically analyze the ECH waves in the Jovian inner magnetosphere, which was surveyed by Juno during the later orbits (>25). We find that in the Jovian inner magnetosphere, ECH waves occur in two specific regions—one equatorial and the other off-equatorial, just outside the Io torus. Equatorial ECH waves have higher intensity compared to their off-equatorial counterpart. We also notice an overlap between the region of mid-latitude hot injections and the region of off-equatorial ECH wave occurrence. Finally, we show an event to describe the complex nature of ECH wave growth/damping varying with particle density structures of the injection region at mid-latitude.

This study used a series of guaiazulenic substituted azobenzene holding chromophores to utilize them in dye-sensitized solar cells (DSSCs). The density functional theory method (B3LYP*/6-311G(d,p)) has investigated these molecules optimized structures and photophysical properties. To conduct the calculation for these molecules electronic absorption spectra, the time-dependent density functional theory (TD‑DFT) method was used. The first principal research has computed the light-harvesting efficiency of electron injection and electronic coupling constant. Transition density matrix (TDM) analysis was used to interpret electronic transformation processes in DSSCs. [ABSTRACT FROM AUTHOR]

The features of the operation of a discharge system based on a planar magnetron with additional electron injection and a conical reflecting electrode are studied. Electrons are injected from a glow discharge with a hollow cathode placed on the back side of the target. The magnetron discharge target with a diameter of 125 mm was made of copper. The pressure of the working gas (argon) varied in the range from 3 to 0.5 mTorr. The discharges functioned in a continuous mode. The results of the effect of the reflecting electrode on the radial uniformity of the generated plasma, as well as the degree of its sputtering, are presented. The radial uniformity and the surface and phase structure of copper films formed when the working pressure decreases down to the lowest possible value (0.5 mTorr) are studied. [ABSTRACT FROM AUTHOR]

We carry out a numerical modeling of plasma injection with hot electrons into a thin layer of cold plasma in the presence of an external magnetic field. We show that the latter can significantly affect the emerging small-scale current filaments and sheets, even if it does not magnetize the particles and does not change the overall dynamics of the redistribution of the total plasma density in the process of injection. The effect observed depends on the orientation of the external magnetic field that is parallel to the plane that bounds the cold plasma layer, if the injection occurs from a narrow strip lying in this plane. In this situation, which corresponds to the ablation of a flat target by a femtosecond laser beam using cylindrical focusing, we study the evolution of the characteristic structures of the formed small-scale magnetic field. It is established that its generation is associated with instabilities of the anisotropic velocity distribution of electrons and that its value can be many times greater than the value of the external magnetic field. [ABSTRACT FROM AUTHOR]

Numerical simulation of the effect of a reflective electrode on the ion composition of the planar magnetron plasma, into the discharge region of which an electron beam with independently controlled electron current and energy is injected, is performed. The numerical simulation results indicate that in such a configuration, higher concentrations of ions of the working gas (argon) and the target cathode (copper) of the magnetron are achieved due to a higher degree of confinement in the region of the plasma generation of injected electrons due to their partial reflection and deflection in the retarding field of the reflective electrode. The simulation results agree satisfactorily with the experimental mass-charge composition of the plasma ions of such a magnetron. [ABSTRACT FROM AUTHOR]

A new photosensitizer 1-WS55 (dyad) based on two dyes with excellent properties, azulenocyanine (1) and WS55, is proposed at the density functional theory level (M06/def2-SVP). 1 is a dye having a broad NIR absorption (~ 1000 nm), and WS55 is a metal-free organic dye that presents a huge photoelectric conversion efficiency (PCE) of 9.5%. The dyad presents a panchromatic absorption along the UV–Vis-NIR region. It exhibits two intense Q bands (880, 926 nm) in the NIR region, one strong band (672 nm) in the visible region, and several bands in 300–600 nm. Charge transfer bands in the dyad from 1 to WS55 were found in the visible region, which favors the adsorption on an anatase TiO2 surface. The interaction energies dyad (dye)-TiO2 were calculated as a periodic system and corrected by the basis set superposition error. These show better adsorption for the dyad than fragments 1 and WS55. The electron injection calculated from the dye (dyad) to TiO2 suggests an efficient solar energy conversion because of ΔGinj > 0.2 eV. Additionally, calculations performed for the reorganization energy of electrons and holes indicate that the dyad presents the highest charge mobility. In summary, the dyad proposed 1-WS55 constitutes an excellent candidate to be used as a potential photosensitizer for the DSSCs. [ABSTRACT FROM AUTHOR]

The special features of the central injection of electrons from the emitter discharge plasma into the discharge system of a planar magnetron are studied. A glow discharge with a hollow cathode and a vacuum arc were used as an emitter discharge. The injection of electrons was carried out through the central hole in the magnetron target. The pressure of the working gas (argon) in the vacuum chamber was 0.05–0.09 Pa in the case of glow discharge emitter. The emitter glow discharge in the hollow cathode functioned in both low‑current continuous mode (10–100 mA) and high-current pulse mode (10–20 A, 25 microseconds, 1 Hz). The vacuum arc emitter operated in pulse mode (10–60 A, 200 microseconds, 1 Hz). Emission currents were measured for various configurations of the discharge system, including the conditions for the complete switching of the electronic component of the emitter current into the discharge system of the magnetron sputter. [ABSTRACT FROM AUTHOR]

Charge carriers' generation from zinc includes silicon quantum dots (ZnSiQDs) layer sandwiched in-between porous silicon (PSi) and titania nanoparticles (TiO2NPs) layer-based solar cell is an efficient way to improve the cell's performance. In this view, ZnSiQDs layer with various QDs sizes have been inserted, separating the PSi and TiO2NPs layers to achieve some graded bandgap quantum dot solar cells (GBQDSCs). In this process, ZnSiQDs of mean diameter 1.22 nm is first prepared via the top-down method. Next, ZnSiQDs have been re-grown using the bottom-up approach to get various mean diameters of 2.1, 2.7 and 7.4 nm. TiO2NPs of mean diameter in the range of 3.2 to 33.94 nm have been achieved via thermal annealing. The influence of different ZnSiQDs sizes on the designed GBGQDSCs performance has been determined. The proposed cell attains a short circuit current of 40 mA/cm2 and an efficiency of 4.9%. It has been shown that the cell performance enhances by optimizing the energy levels alignment in the PSi, ZnSiQDs, TiO2NPs layers. [ABSTRACT FROM AUTHOR]

• Chloride modification accelerate electron injection. • Chloride modification position is critical for ion migration. • The dense and smooth film facilitate better electrochemical behavior. • Supercapacitor had high cycle stability, maintaining 78% after 10,000 cycles. Ambipolar conducting polymer electrode materials exhibit a wide voltage window, contributing to fast development of high-energy–density storage devices. The doping levels of p-doped and n-doped in ambipolar conducting polymers determine the electrochemical performance of energy storage devices. However, n-doped materials always face low doping efficiency, caused by difficulty in electron injection and ion migration, thereby affecting specific capacitance and stability. In this study, two ambipolar conductive polymers were developed, in which the n-doped imine group was chlorinated to improve electron injection, and the mechanism of ion migration process was studied by changing the chlorination of different positions relative to the carbonyl group. The influence of chloride modification on n-doped electrochemical energy storage was thoroughly investigated. The results show that chloride modification can lower the lowest unoccupied molecular orbital (LUMO) energy level of the monomer and make electron injection easier. Interestingly, the chloride modification position not only affects the oxidation–reduction of the carbonyl, but also the binding of the carbonyl with lithium ions. If the chloride modification position is too close to the carbonyl, lithium-ion migration in ambipolar conducting polymer will be restricted, although electron injection is beneficial. Based on this design, the developed PEPCl conducting polymer exhibits excellent electrochemical performance, and the mechanism of chlorination modification of ambipolar polymer electrode materials is described. [ABSTRACT FROM AUTHOR]

[Display omitted] • The new acceptor groups have been designed. • Designed dyes 5 and 9 TCNQ derivatives exhibit the maximum absorption wavelength. • The designed molecules were exhibited gigantic second order nonlinear optical response. Systematic strategies have been employed to designing the acceptor part for dye sensitized solar cell and nonlinear optical properties using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. The designed dyes have followed donor-π-spacer-acceptor (D-π-A) pattern. For designing of organic dyes, we have utilized the 7,7,8,8-tetracyanoquinodimethane (TCNQ) unit as a accepter for dye-sensitized solar cells (DSSCs) and investigating the impact of various electron acceptor in the designed framework. For designing of such framework, we have employed B3LYP level of theory and 6–311+G(d,p) basis set. Initially, the optoelectronic properties of the metal free dyes are calculated based on different acceptors and then we have designed (2– 9) dyes. The designed dyes which contain TCNQ-based acceptors show enhance power conversion and optoelectronic properties than that of reference one. We have calculated different parameters such as dipole moments (μ normal), band gap (E gap), electron injection (ΔG injection), driving force of regeneration (ΔG regen), and nonlinear optical (NLO) properties. We have also investigated the essential process of dye adsorption on titanium dioxide (TiO 2) surfaces. The calculated values of μ normal (17.79 & 22.37 debye) and E gap (0.57 & 0.88 eV) for dyes 8 & 9 respectively which are more efficient than that of dye 1. Furthermore, the calculations for density of state (DOS) and partial density of state (PDOS) validate the FMO analysis and demonstrate effective charge transfer from the HOMO to LUMO. Further, the designed dye molecules were exhibiting enhanced and gigantic nonlinear optical properties. In comparison to cyanoacrylic acid, the TCNQ group has the potential to function as a superior acceptor in upcoming applications of DSSCs. [ABSTRACT FROM AUTHOR]

Abstract Here, this work presents an air-stable ultrabright inverted organic light-emitting device (OLED) by using zinc ion-chelated polyethylenimine (PEI) as electron injection layer. The zinc chelation is demonstrated to increase the conductivity of the PEI by three orders of magnitude and passivate the polar amine groups. With these physicochemical properties, the inverted OLED shows a record-high external quantum efficiency of 10.0% at a high brightness of 45,610 cd m−2 and can deliver a maximum brightness of 121,865 cd m−2. Besides, the inverted OLED is also demonstrated to possess an excellent air stability (humidity, 35%) with a half-brightness operating time of 541 h @ 1000 cd m−2 without any protection nor encapsulation.

The metal‐oxide semiconductors exhibit remarkable optoelectronic properties and have immense implication in applications involving energy conversion, light emission, environmental remediation, etc. The presence of metal nanostructures in titanium dioxide (TiO2), zinc oxide metal‐oxide semiconductors have enhanced the photo‐activity, due to the plasmon resonances and are predominantly researched for organic and perovskite photovoltaics. Generally, the metal nanoparticle dopants are introduced by methods like sputtering, sol–gel, etc. However, compared with conventional doping methods, ion‐implantation technique is a purely physical process, and a high controllability and repeatability can be achieved. Here, the current status of synthesis of nanocomposites in TiO2‐based photo‐anodic applications by ion‐implantation method is reviewed, and there is no elaborate review on this topic. Finally, the future prospects of ion‐implantation technique for controlling the excitonic behavior in TiO2 are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dye aggregation on TiO 2 films could be regulated by the solvent of dye bath. • J-Aggregation induces higher long-wavelength absorption than H-aggregation. • Charge-separated dye aggregation has no adverse effects for electron injection. • J-Aggregation of charge-separated dye greatly enhanced the photocurrent of DSSCs. Aggregation of organic molecules plays a key role in determining the photoelectronic properties of various devices. However, the formation of aggregates is an outcome of complex synergistic effects of various intermolecular forces, and changes with the molecular structure and environment. Here we exploit the aggregation of two dyes with (MTPABT-Pyc) or without (MTPAcc) the nanosecond long-lived charge separation state and their effect on photovoltaic performance of dye-sensitized solar cells (DSSCs). Different solvent systems were selected to modulate the interactions between solvents and dye molecules for the effects on photophysical processes. Combining the experimental results on the solvent effect on dye aggregation with theoretical calculations reveals that MTPAcc inclines to form H -aggregation on the TiO 2 surface because of the decisive role of its molecular structure. The solvent regulation has a great impact on MTPABT-Pyc which can make aggregates transform between H -aggregation and J -aggregation. The effects of aggregation on the device performance of two dyes are completely opposite. High performance of MTPAcc depends on the co-adsorbent chenodeoxycholic acid, which could suppress the dye aggregation. In contrast, the aggregation of MTPABT-Pyc will not harm the charge separation and transportation processes in devices and shows a positive effect on the cell performance due to the aggregation exhibiting broader absorption bands. As the photocurrent contribution by the aggregation-induced long-wavelength absorption increases from 9% (H -aggregation) to 34% (J -aggregation), the short-circuit current (J sc) and the power conversion efficiency (PCE) of MTPABT-Pyc increased by 13% and 14%, respectively. These results pave a new way for taking full advantage of the aggregation of molecules to realize high-performance light-to-current conversion. [ABSTRACT FROM AUTHOR]

In this work, a silicon-on-insulator (SOI)-based lateral avalanche photodiode (APD) is proposed and fabricated. The device features lateral separate-absorption-multiplication (SAM) and electron-only injection. The bandwidth is optimized with the effective blocking of the deep photogenerated carriers by SOI structure. The device stability is also improved by additional shallow P-well region near the N+-region which can eliminate the edge breakdown induced by the curvature effect. Simulation results demonstrate that avalanche region (high electric field zone) is confined at the lateral PN+ junction. Experimental fabrication and characterizations are further realized, and this SOI-based lateral APD device exhibits high responsivity (1.92 A/W at 7.8 V for 300 nm), low dark current (below 5 V), large bandwidth (12.4 GHz at 8.2 V), and low breakdown voltage (~7.8 V). The demonstrated device performance as well as the simple structure and good process compatibility can be attractive in future photo-detecting and advanced sensing applications. [ABSTRACT FROM AUTHOR]

Stable film formation and interface control of electron-transporting polymers are important key issues for developing organic devices. In this report, thin films of N,N' -bis(p -vinylbenzyl)naphthalenediimide (PVB-NDI) were prepared by the vapor deposition and an electron-assisted (e-assist) deposition methods on aluminum substrates. The aluminum surface was modified with self-assembled monolayers (SAMs) of (3-mercaptoprppyl) trimethoxysilane (MPTMS) or vinyltriethoxysilane for controlling the film/substrate interface. It was observed that the e-assist deposition can polymerize PVB-NDI in the process of film deposition. The polymerization was induced by the e-assist process, and was not influenced by the surface modification with the SAMs. It was found that the electron injection barrier height can be substantially decreased when the PVB-NDI film was prepared by the e-assist deposition on the aluminum surface modified with the SAM of MPTMS. This result implies that covalent tethering via the thiol-en reaction at the interface contributes to controlling the metal/organic interface. [ABSTRACT FROM AUTHOR]

We have found that the work function of aluminum can be reduced to about 2.0 eV by using a superbase as an electron injection layer. This extremely low work function enabled us to gain a complete understanding of the electron injection/transport mechanism in OLEDs. [ABSTRACT FROM AUTHOR]

This study explores the challenges to photo-reforming sacrificial chemicals into beneficial by-products while improving photocatalytic activity in H 2 O 2 production by addressing several issues. The resorcinol-formaldehyde/graphitic carbon nitride composite (RF 0.2 GCN) with nanosheet-like RF morphology achieved a higher degree of surface-to-surface contact through -C-NH-CH 2 - and -NH-CH-OH than the nanosphere (RF 0.8 GCN). The RF 0.2 GCN produced H 2 O 2 at 325.2 µg g−1 s−1 in the presence of oxalic acid (OA) at pH 2.1 with apparent quantum yield (AQY) of 12.7 %. The conduction band position potential was +0.54 V NHE , which is thermodynamically unfavorable for H+/H 2 (E°: 0.00 V NHE) and O 2 / · O 2 - (E°: −0.046 V NHE) reaction and also inhibits the decomposition of H 2 O 2 (H 2 O 2 / · OH, E°: +0.39 V NHE). Furthermore, the decomposition of OA formed formic acid (FA) at 82 % selectivity and concurrent CO 2 · - formation could promote electron density in the conduction band via its electron-donating ability·H 2 O 2 was purified by isolating FA using anion exchange resin, and FA was recovered by desorption from the resin using HCl (pH 3). [Display omitted] • Nano-sheets stacking facilitates LLCT between the two photocatalysts. • Upcycling sacrificial chemicals into valuable chemical by-products. • Suitable band position for desirable direct O 2 → H 2 O 2 pathway. • Simultaneous production of hydrogen peroxide and formic acid. • Hydrogen peroxide and formic acid separation by ion-exchange resins. [ABSTRACT FROM AUTHOR]

Zinc oxide (ZnO) has attracted lots of attention to be used as interfacial materials in organic optoelectronic devices owing to its attractive properties. In this work, a series of transition-metal-doped ZnO thin films were prepared by using a facile aqueous solution process, thereafter these films were employed as electron injection layers (EILs) combined with the tris-(8-hydroxyquinoline) aluminum (Alq 3) emitting layer to construct the inverted organic light-emitting diodes (IOLEDs). The transition-metal-doped ZnO EIL-based IOLEDs demonstrate markedly improved device performance compared to the reference neat ZnO EIL-based IOLED. However, different transition-metal ions have much different doping effect on the device performance. CoCl 2 doped ZnO EIL based IOLED device possesss an optimal current efficiency of 5.52 cd A−1, which is increased about 40% compared to the device with the neat ZnO as EIL. The enhancement might be attributed to the increased electron mobility and favorable interfacial energy level alignment of the transition-metal doped ZnO EIL for more efficient electron injection. Our findings may provide a promising strategy to improve the electron injection properties of ZnO film in the OLED devices. • The transition-metal-doped ZnO films were used as the electron injection layers in OLEDs. • Transition-metal-doped ZnO films were prepared by using a facile aqueous solution process. • The transition-metal doping increased the electron injection efficiency of the OLEDs. [ABSTRACT FROM AUTHOR]

• Dual side transparent OLED devices with an Ag top cathode are achieved. • The efficient electron injection is fulfilled by inserting a 3 nm thick LiF layer. • Different from LiF/Al, the working mechanism of LiF/Ag cathode is tunneling mode. • A MoO 3 dielectric layer is capped on Ag cathode for light extraction. • Light extraction is greatly improved by the capping layer in terms of EL properties. Transparent organic light-emitting diodes (TrOLEDs) offer enormous promising applications in next-generation consumer electronic devices. Herein, TrOLEDs based on a silver (Ag) top cathode are fabricated via vacuum deposition. The semi-transparent and efficient Ag cathode has been fulfilled by combining the optimization of the thickness and deposition rate of Ag films with the modification of lithium fluoride (LiF) and molybdenum trioxide (MoO 3). The introduction of an optimal LiF layer is beneficial for electron injection, which could be explained by tunneling model due to its insulation property. And a MoO 3 dielectric layer is capped on Ag cathode for light extraction due to its high refraction index. The electroluminescent (EL) properties collected from the top Ag cathode side are remarkably improved by the capping MoO 3 dielectric layer while maintaining the EL performance collected from the bottom anode side. This work provides a meaningful guidance for the construction of TrOLEDs. [ABSTRACT FROM AUTHOR]

Azole derived products acquired significant consideration in everyday life based on their improved biological potential to the semiconducting substances. The research focused in-depth within pyrazol, and oxazole compounds 1–4 concerning charge transport, structural, optical as well as electronic properties. The density functional theory (DFT) along with time-dependent DFT were used for the optimization of their ground state geometries and excitation energies. We also investigated the molecule's electron coupling constants (|VRP|) as well as electron injection (ΔGinject) values. For better understanding, charge transport and electronic characteristics were performed through quantum chemical computations. The |VRP| and ΔGinject values of pyrazole, as well as oxazole molecules, exhibited that these compounds could be competent for dye-sensitized solar cell applications. The pyrazole higher diagonal band gap enlightening these might have enhanced fill factor (FF) along with short-circuit current density (Jsc). We have also explored the electron injection, energy level offset, dissociation of excitons, and band alignment of studied compounds to shed light on the functionality of these compounds for photovoltaic and semiconductor device applications. [ABSTRACT FROM AUTHOR]

Highlights: By using a zinc ion-chelated polyethylenimine as electron injection layer, an inverted organic light-emitting device (OLED) was successfully prepared with an external quantum efficiency over 10% at a brightness of 45,610 cd m−2. The chelation between zinc ion and amine groups not only passivates polar amine groups, but also fuses separated electronic orbitals. The inverted OLED show an excellent air stability with an operating time of 541 h @ 1,000 cd m−2 without any protection. Here, this work presents an air-stable ultrabright inverted organic light-emitting device (OLED) by using zinc ion-chelated polyethylenimine (PEI) as electron injection layer. The zinc chelation is demonstrated to increase the conductivity of the PEI by three orders of magnitude and passivate the polar amine groups. With these physicochemical properties, the inverted OLED shows a record-high external quantum efficiency of 10.0% at a high brightness of 45,610 cd m−2 and can deliver a maximum brightness of 121,865 cd m−2. Besides, the inverted OLED is also demonstrated to possess an excellent air stability (humidity, 35%) with a half-brightness operating time of 541 h @ 1000 cd m−2 without any protection nor encapsulation. [ABSTRACT FROM AUTHOR]

Manganese-based oxides (MnO x ) suffer from sluggish charge diffusion kinetics and poor cycling stability in sodium ion storage. Herein, an interfacial electric field (IEF) in CeO 2 /MnO x is constructed to obtain high electronic/ionic conductivity and structural stability of MnO x . The as-designed CeO 2 /MnO x exhibits a remarkable capacity of 397 F g -1 and favorable cyclic stability with 92.13% capacity retention after 10,000 cycles. Soft X-ray absorption spectroscopy and partial density of states results reveal that the electrons are substantially injected into the Mn t 2g orbitals driven by the formed IEF. Correspondingly, the MnO 6 units in MnO x are effectively activated, endowing the CeO 2 /MnO x with fast charge transfer kinetics and high sodium ion storage capacity. Moreover, In situRaman verifies a remarkably increased structural stability of CeO 2 /MnO x , which is attributed to the enhanced Mn─O bond strength and efficiently stabilized MnO 6 units. Mechanism studies show that the downshift of Mn 3d-band center dramatically increases the Mn 3d-O 2p orbitals overlap, thus inhibiting the Jahn-Teller (J-T) distortion of MnO x during sodium ion insertion/extraction. This work develops an advanced strategy to achieve both fast and sustainable sodium ion storage in metal oxides-based energy materials., (© 2024 Wiley‐VCH GmbH.)

Surface defect passivation and carrier injection regulation have emerged as effective strategies for enhancing the performance of perovskite light-emitting diodes (Pero-LEDs). It usually requires two functional molecules to realize defect passivation and carrier injection regulation separately. In other words, developing one single molecule possessing these capabilities remains challenging. Herein, we utilized π-conjugated fluorene derivatives as surface treatment materials, 9,9-Spirobi[fluorene] (SBF), 9,9-Spirobifluoren-2-yl-diphenylphosphine oxide (SPPO1), and 2,7-bis(diphenylphosphoryl)-9,9'-spirobifluorene (SPPO13), to investigate the influence of their chemical structure on device optoelectronic performance, especially for defect passivation and carrier injection regulation. Consequently, the passivation capability of double-bonded SPPO13 surpassed single-bonded SPPO1 and nonbonded SBF, which all showed excellent electron transport properties, enhancing electron injection. The maximum external quantum efficiencies (EQE) for Pero-LEDs treated with SBF, SPPO1, and SPPO13 were 8.13, 17.48, and 22.10%, respectively, exceeding that of the derivative-free device (6.55%). Notably, SPPO13-treated devices exhibited exceptional reproducibility, yielding an average EQE of 20.00 ± 1.10% based on 30 devices. This result emphasizes the potential of tailored fluorene derivatives for enhancing the device performance of Pero-LEDs.

Charge carriers’ generation from zinc includes silicon quantum dots (ZnSiQDs) layer sandwiched in-between porous silicon (PSi) and titania nanoparticles (TiO2NPs) layer-based solar cell is an efficient way to improve the cell’s performance. In this view, ZnSiQDs layer with various QDs sizes have been inserted, separating the PSi and TiO2NPs layers to achieve some graded bandgap quantum dot solar cells (GBQDSCs). In this process, ZnSiQDs of mean diameter 1.22 nm is first prepared via the top-down method. Next, ZnSiQDs have been re-grown using the bottom-up approach to get various mean diameters of 2.1, 2.7 and 7.4 nm. TiO2NPs of mean diameter in the range of 3.2 to 33.94 nm have been achieved via thermal annealing. The influence of different ZnSiQDs sizes on the designed GBGQDSCs performance has been determined. The proposed cell attains a short circuit current of 40 mA/cm2 and an efficiency of 4.9%. It has been shown that the cell performance enhances by optimizing the energy levels alignment in the PSi, ZnSiQDs, TiO2NPs layers.

2H MoS2 nanoflakes were exfoliated and surface-modified by amine (-NH2) groups in a simple three-step water-based approach. The NH2-modified MoS2 sheets were used as humidity sensitive layer for estimating various levels of relative humidity (RH) (10%–90%). The devices demonstrated a maximum response of 720% for 90% RH with ${t}_{{\text {response}}} =1.2$ s and ${t}_{{\text {recovery}}} =3.1$ s, respectively, when operated at 1 V. The device also displayed low hysteresis and good stability with a maximum error in response to ±5% when tested for 50 days. The device demonstrated a good response at lower RHs. To explain this enhancement of response, a novel “pseudo electron injection model” has been put forward. It established that the enhanced response was due to the increased electron transfer from the MoS2–NH2 system (with lone pairs) to the humidity layer resulting in an electron accumulation at the MoS2 layer, and thus lowering the conduction band minima (CBM) of the MoS2 system beneath. This accumulation amplified the device current significantly resulting in sensor performance enhancement. The CBM-lowering and electron population due to this pseudo electron injection were expressed as a function of the thickness of adsorbed humidity and the MoS2–NH2 layers, thereby finally expressing the enhanced response. From the models, extinction coefficients affecting CBM-lowering were calculated as $\alpha = -0.042$ eV and $\beta = -0.49$ eV nm−1 which supported the obtained results. [ABSTRACT FROM AUTHOR]

Two perylene monoanhydride (PMA) based dyes (P1 and P2) were designed, synthesized and used as sensitizers for dye-sensitized solar cells (DSSCs) for the first time. The sensitizers were characterized well using 1H NMR, High Resolution Mass Spectrometry (HRMS) and FTIR techniques. The solvatochromic effect and the interaction of dye molecules with solvents were studied using absorption and emission spectra in different solvents. The highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) and absorption maxima (λmax) values calculated by density functional theory were consistent with the corresponding experimental values. The HOMO and LUMO levels of the sensitizers suppose the efficient and thermodynamically favorable electron injection and dye regeneration process of DSSCs. The higher binding ability of P1 with TiO2 in the ground state and excited state was demonstrated using absorption and emission spectra respectively. The fabricated DSSC using P1 showed higher power conversion efficiency of 0.22% than the DSSC fabricated using P2 of 0.19%. The higher efficiency of P1 was verified with the higher value of electron recombination (∆Grec) than that of P2. The energy level diagram and electron transfer process of DSSCs were also illustrated schematically. [ABSTRACT FROM AUTHOR]