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Over the recent past, lead-based halide perovskite materials have drawn significant attention due to their excellent optical and electrical properties for solar cells and optoelectronics applications. However, the toxicity of lead elements and instability under ambient conditions leads to develop alternative compositions. Herein, we report a novel mechanochemical synthesis of tin iodide-based double perovskites (A2SnI6; A = Rb+, Cs+, methylammonium, and formamidinium), and their structural, optical, and electrical properties are investigated. Importantly, we found that the hydrogen iodide (HI) addition during the ball-milling process minimizes secondary phase formation in the synthesized A2SnI6 powders. The effects of HI addition and the A-site substitution are investigated with respect to the lattice parameters, optical bandgaps, and electrical properties of the synthesized perovskite materials. Our results demonstrate essential information to improve the understanding of halide perovskite materials and develop efficient lead-free perovskite photoelectric devices.

We develop the effective modification strategy based on molecular engineering of s-triazine and its derivatives to improve the photoelectric performance of all-inorganic perovskites (AIP) for the first time. The surface modification strategy with cyanuric acid successfully increases the PLQY of AIP from 40.55% to 88.15%, and significantly enhances the current of the AIP film under 3 V by almost 20-fold (from 4.44 mA to 81.20 mA). This work has proven the effectiveness of improving the photoelectric performances of AIP via s-triazine and its derivatives and also suggested the potential risks of reducing the photoelectric performance of AIP due to inappropriate substituents in conjugated organic ligands.

In the radiation protection application, the metal-polymer composites have been developed for their radiation shielding properties. In this research, the elastomer composites doped by 10 μm and100nm size of lead, bismuth and tungsten particles as filler with 30 and 60 wt percentages were prepared. To survey the shielding properties of the polymer composites using gamma-ray emitted from 152Eu and 137Cs sources, the gamma flux was measured by using NaI(Tl) detector, then the linear attenuation coefficient was calculated. Also, the Monte Carlo simulation (MCs) method was used. The results showed a direct relationship between the linear attenuation coefficients of the absorbent and filler ratio. Also, the decrease in the particle size of the shielding material in each weight percentage improved the radiation shielding features. When the dimension of the particles was in the order of nano-size, more attenuation was achieved. At low energies used for medical diagnostic X-ray applications due to the predominance of the photoelectric effect, bismuth and lead were suitable selection as filler.

The complex physical and chemical interactions between DNA and 0-3 eV electrons released by UV photoionization can lead to the formation of various lesions such as base modifications and cleavage, crosslinks and single strand breaks. Furthermore, in the presence of platinum chemotherapeutic agents, these electrons can cause clustered lesions, including double strand breaks. We explain the mechanisms responsible for these damages via the production 0-3 eV electrons by UVC radiation, and by UV photons of any wavelengths, when they are produced by photoemission from nanoparticles lying within about 10 nm from DNA. We review experimental evidence showing that a single 0-3 eV electron can produce these damages. The foreseen benefits UV-irradiation of nanoparticles targeted to the cell nucleus are mentioned in the context of cancer therapy, as well as the potential hazards to human health when they are present in cells.

The relationship between the aggregation states of pyrene-based linkers and the photoluminescence/photoelectric performance was well studied by the formation of an anionic metal-organic framework, [BMI]2[Mg3(TBAPy)2(H2O)4]·2dioxane, which shows highly enhanced light-harvesting and photoelectric conversion efficiency by the encapsulation of D-π-A cation dyes.

Organic solar cells are a current research hotspot in the energy field because of their advantages of lightness, translucency, roll to roll printing and building integration. With the rapid development of small molecule acceptor materials with high-performance, the efficiency of organic solar cells has been greatly improved. Further improving the device efficiency and stability and reducing the cost of active layer materials will contribute to the industrial development of organic solar cells. As a novel type of carbon nanomaterials, carbon dots gradually show great application potential in the field of organic solar cells due to their advantages of low preparation cost, non-toxicity and excellent photoelectric performance. Firstly, the synthesis and classification of carbon dots are briefly introduced. Secondly, the photoelectric properties of carbon dots and their adjusting, including adjustable surface energy level structure, good film-forming performance and up/down conversion characteristics are summarized. Thirdly, based on these intrinsic properties, the feasibility and advantages of carbon dots used in organic solar cells are discussed. Fourthly, the application progress of carbon dots in the active layer, hole transport layer, electron transport layer, interface modification layer and down-conversion materials of organic solar cells is also reviewed. Finally, the application progress of carbon dots in organic solar cells is prospected. Several further research directions, including in-depth exploration of the controllable preparation of carbon dots and their application in the fields of interface layer and up/down conversion for improving efficiency and stability of device are pointed out.

In this paper, an optimal design method of micro-lens light trapping structure for thin film solar cells applied to building integrated photovoltaic (BIPV) is proposed. Under three common scenes of BIPV, including lighting roof, sunshade and building facade, the optimal design and photoelectric performance study of Copper Indium Gallium Selenium (CIGS) thin film solar cells with micro-lens light trapping structure are studied. Among the three kinds of micro-lens light trapping structures, V-shaped, semi-cylindrical and concave, the light capture performance of V-shaped micro-lens light trapping structure is the best. The V-shaped micro-lens light trapping structure with a vertex angle of 70° and a groove depth of 100 μm has the best light capture performance in lighting roof and sunshade scene, which can increase the annual radiation flux of the absorption layer incident surface by 4.45% and 2.84% respectively. The V-shaped micro-lens light trapping structure with a vertex angle of 60° and a groove depth of 200 μm has the best light capture performance in building facade scene, which can increase the annual radiation flux of the absorption layer incident surface by 7.63%. When the light source is vertically incident, these two V-shaped micro-lens light trapping structures can increase the short-circuit current density by 15.57% and 7.11% respectively.

In this work, UV light activated multi-cycle photoelectric properties of TiO2 and CdS/TiO2 films in formaldehyde were researched. TiO2 film was prepared by screen printing, CdS/TiO2 compounded film was synthesized by SILAR method. XRD and FE-SEM was used to characterize the TiO2 and CdS/TiO2 samples. Multi-cycle photoelectric properties of TiO2 and CdS/TiO2 with uv light on and off were evaluated by testing the photocurrent. On one hand, under the same bias voltage, CdS/TiO 2showed a higher photocurrent than that by TiO2. The reason for this result should be ascribed to the compounded structure in CdS/TiO2, with which the separation and transfer of photogenerated electron-hole pairs could be improved. On the other hand, with the testing cycle number increased, the photocurrent amplitudes of TiO2 and CdS/TiO2 increased. These results suggested that the time to reach a stable photocurrent value for TiO2 and CdS/TiO2 is much longer than one cycle time (300 S). To illustrate the increased photocurrent amplitude value cycle by cycle, the photocurrent of CdS/TiO2 to a much longer time (more than 4000 seconds) was also tested. To explain these results, corresponding possible illustrations were presented.

Modulating the crystal field environment around the emitting ions is an effective strategy to improve the luminescence performance of the practical effective phosphor materials. Here, smaller Y3+ ions are introduced into substituting the Gd3+ sites in Ba2GdNbO6:Mn4+ phosphor to modify the optical properties, including the enhanced luminescence intensity, redshift, and longer lifetime of the Mn4+ ions. The substitution of smaller Y3+ ions leads to lattice contraction and then strengthens pressure on the local structure, enhances lattice rigidity, and suppresses nonradiative transition. Moreover, the prototype phosphor-converted light-emitting diode (LED) demonstrates a continuous change photoelectric performance with a correlated color temperature of 4883-7876 K and a color rendering index of 64.1-83.2, suggesting that it can be one of the most prospective fluorescent materials applied as a warm red component for white LEDss. Thus, the smaller ion partial substitution can provide a concise approach to modulate the crystal field environment around the emitting ions for excellent luminescence properties of phosphors toward the modern artificial light.

Perovskite/silicon tandem solar cell (TSC) is a promising strategy to receive high power conversion efficiency (PCE), exceeding the Shockley-Queisser (S-Q) limit of single junction SC. However, the reflected light still dominates the loss of photocurrent, happened at the surface and interface of two sub cells. Here, a suitable spacer layer is accepted to manage the light harvesting in the four-terminal (4T) perovskite/silicon TSC. The influence of microstructure, refractive index and thickness of spacer layer on the photocurrent has been systematically studied by the photoelectric simulation. And then the designed spacer layer is a double-side textured structure with a refractive index (RI) of 1.4 in 4 μm thickness, receiving the best light-harvesting to being the largest photocurrent. Furthermore, the relationship of light-absorption between perovskite and silicon SCs is investigated as a function of bandgap and thickness of perovskite, yielding the optimal photocurrent of 21.65 mA/cm2 and 19.71 mA/cm2 for top and bottom cells, respectively. Finally, four types of industrialized silicon SCs are integrated into the TSCs to study the photoelectric performance in detail, predicting the theoretical limitation PCE of 33.52%. Therefore, this simulated study provides a theoretical guide for the optical design of high-efficiency 4T TSCs.

Recently, newly emerging halide perovskites have aroused intensive attention in photoelectric fields in virtue of their good properties, such as well-balanced carrier transport, large light absorption coefficient, tunable band gap, and low-temperature solution processing technique. Nevertheless, their future commercial development is severely hampered by lead toxicity and instability of such materials. In this work, one-dimensional Rb2CuBr3 single-crystal microwires (MWs) were prepared by antisolvent engineering, and they were further employed as absorbers to prepare sensitive ultraviolet (UV) photodetectors. The optical band gap of Rb2CuBr3 MWs is measured to be 3.83 eV, exhibiting an excellent UV absorption. The fabricated device demonstrates a remarkable UV light detection ability with a specific detectivity of 1.23 × 1011 Jones, responsivity of 113.64 mA W-1, and response speed of 69.31/87.55 ms under light illumination of 265 nm. Meanwhile, the proposed photodetector without any encapsulation shows outstanding stability and repeatability. After storing in ambient air for 2 weeks, the light detection ability remains basically unchanged. Further, a flexible photodetector was fabricated with the same structure, which demonstrates a remarkable bending endurance. These results confirm the great potential of Rb2CuBr3 for high-performance UV photodetectors, increasing the possibility for assembly of optoelectronic systems.

Hundreds of C60 derivatives stand out as electrontransporting materials(ETMs), for example, in perovskite solar cells(PSCs), due to their properties on electron extraction or defect passivation. However, it still lacks of guidelines to update C60-based ETMs with excellent photoelectric properties. In this work, crystallographic data of eight C60-based ETMs, including pristine C60 and the well-known PCBM as well as six newly synthesized fullerenes, are analyzed to establish the connections between derivatized structures and photoelectric properties for the typical carbon cluster of C60. In terms of packing centroid-centroid distance between neighboring carbon cages, the crystallographic data are useful for probing photoelectric properties, such as electrochemical properties, electron mobility and photovoltaic performances, and therefore facilitate to design novel C60-based ETMs for PSCs with high performances.

Bismuth-based compounds possess layered structures with a variety of stacking modes, endowing the compounds with diverse properties. As one type of bismuth oxysulfides, Bi9 O7.5 S6 nanocrystals has great applications in photodetection; however, the responsivity of bulky Bi9 O7.5 S6 is limited due to the poor charge separation. Herein, single-crystalline Bi9 O7.5 S6 thin nanosheets are successfully synthesized by using a solvothermal method. The thickness of the obtained Bi9 O7.5 S6 nanosheets is down to 15 nm and can be easily tuned by varying the reaction period. Moreover, the Bi9 O7.5 S6 nanosheets show strong light absorption in the visible and near infrared range, making it a promising candidate in optoelectronics. As a demonstration, the thin Bi9 O7.5 S6 nanosheets are used as active layer in an optoelectronic device, which exhibits sensitive photoelectric response to light in a wide range of 400-800 nm. The responsivity of the device reaches up to 1140 μA W-1 , and the performance of the device is stable after long-period illumination. This work demonstrates a great potential of the thin Bi9 O7.5 S6 nanosheets in optoelectronic devices, and these nanosheets may also be extended to various optoelectronic applications.

As an early-stage tumor biomarker, microRNA (miRNA) has clinical application potential and its sensitive and accurate detection is significant for early tumor diagnosis. In this study, a photoelectrochemical (PEC) biosensing platform was fabricated for ultrasensitive miRNA-141 detection, which is based on a photocurrent polarity-switchable system using CdS quantum dots (QDs) in the presence of a 5,10,15,20-tetrakis (4-aminophenyl)-21H,23H-porphine (Tph-2H)-coated glassy carbon electrode (GCE). As an excellent photoactive material, Tph-2H has a narrow band gap that effectively gathers photoelectrons under visible light irradiation and improves the transfer ability of photogenerated electrons. Further, the detection sensitivity of miRNA-141 could be significantly improved by combining an enzyme-assisted recycle amplification reaction and a magnetic bead-based separation strategy. The proposed photocurrent polarity-switchable PEC biosensor could efficiently eliminate the false-positive or false-negative signals and achieve a wide linear response range from 1 fM to 1 nM with a low detection limit of 0.33 fM for miRNA-141, providing a potentially alternative solution for detecting other biomarkers in bioanalysis and clinical diagnosis.

The Sentaurus TCAD software package is widely used in the modeling of semiconductor optoelectronic devices. The main part of simulating solar elements is creating a correct geometric model. A geometric model can be built using the SDE module in two different ways, i.e. by writing code or using standard shapes in a graphical environment. Creating complex structures using simple shapes is time-consuming and labour intensive. Therefore, this paper provides data on how to develop algorithms using geometric models of complex structural solar cells. A universal algorithm has been developed for creating a geometric model of solar cells with a sinusoidal p-n junction and a rear multiple structure. Using these algorithms, it is possible to create geometric models of various solar cells from simple to complex structures. By applying this algorithm, the authors studied the dependence of photoelectric parameters of the p-n and n-p junction silicon solar cells on their thickness in order to find the optimum thickness for both structures. It has been found, that the optimum thickness was equal to 256 μm for p-n junction and 75 μm for n-p junction silicon solar cell. The maximum efficiency of p-n junction silicon solar cell is 1.4 times greater than that of n-p junction solar cell in their optimum thickness.

This work outlines a new instructional laboratory experiment focused on the photoelectric effect and the determination of Planck's constant. The described laboratory system employs contemporary experimental techniques, including real-time data acquisition based on the use of Arduino boards. The basis of this experiment is to measure the associated turn-on voltages of a small neon bulb as it is illuminated with several different optical wavelengths. Six different LED and laser illumination sources were used with wavelengths ranging from UV (383 nm) to red (659 nm). A plot of the bulb's turn-on voltage as a function of the inverse of the excitation wavelength showed a linear relationship with a high correlation coefficient. Planck's constant was determined from this plot, yielding a value of h=7.4±1.1×10−34 J·s. Additionally, the system allows for experimental verification of the independence between excitation light intensity and the energy needed to ionize the gas inside the bulb.

Lead halide perovskite quantum dots (QDs) are known as prospective optoelectronic device materials because of their excellent luminescence, extraordinary photoelectric performance, and specific octahedron framework. Herein, we report a cost-effective approach for synthesizing highly stable CH3NH3PbBr3 QDs in low-polarity binary solvents without nitrogen protection. The CH3NH3PbBr3 QDs are tunable from 1.2 to 4.2 nm by adjusting the proportion of oleic acid and oleylamine as capping ligands. The photoluminescence quantum yield of CH3NH3PbBr3 QDs can reach 87.4%. The fluorescence can maintain over 80% of its earliest emission intensity under the atmosphere after 5 days, which is much better than that (∼10%) of QDs with ligand-assisted reprecipitation. The possible reaction mechanism of preparing CH3NH3PbBr3 QDs was also addressed. Notably, such a strategy can be applied extensively in the preparation of other lead halide perovskite QDs. Furthermore, the as-prepared thick PMMA-coated CH3NH3PbBr3 QDs were further conjoined with a red luminescence powder on a blue InGaN chip to obtain a powerful efficiency (45.4 lm W-1) warm white light-emitting diode.

The influence of different types of π-bridges in triphenylamine-based organic sensitizers on their photophysical and photovoltaic properties is investigated by using sophisticated first-principles calculations and reliable theoretical models. Two well-designed strategies, namely the cyclization between separate benzothiadiazole and bithiophene as well as the insertion of electron-rich/deficient groups between the rigidly fused π-bridge and anchor moieties are proposed. It is found that the calculated photophysical and photovoltaic parameters of the dye with an unfused π-bridge reproduce very well the available experimental data, ensuring the rationality of present theoretical methods and models. The designed dye featuring a rigidly fused π-bridge shows a remarkable decrease of power conversion efficiency (PCE), with respect to the dye with an unfused π-spacer (6.36% vs. 11.18%), which implies that simply cyclizing separate aromatic heterocyclic groups is unfavorable for improving the photoelectrical performance. However, the PCE can be increased to 14.20% when an electron-rich thiophene group is introduced between the fused π-bridge and the anchor units. More importantly, replacing the thiophene moiety with an electron-deficient benzothiadiazole group can further improve the photovoltaic performance, and consequently a PCE as high as 23.81% is achieved, which is a significant theoretical improvement for triphenylamine-based organic dyes. To sum up, this study theoretically elucidates the effect of unfused and fused π-bridges as well as the introduction of electron-rich/deficient groups in organic dyes on their photophysical and photoelectric properties and provides a useful guidance for further designing highly-efficient dye sensitizers by molecular engineering.

Self-powered sensors can lead to disruptive advances in self-sustainable sensing systems that are imperative for evolving human lifestyles. For the first time, we demonstrate the fabrication of a heterojunction sensor using p-type hybrid-halide perovskites (CH3NH3PbBr3) and an n-type semiconducting metal oxide thin film [InGaZnO (IGZO)] for the detection of NO2 gas and power generation. Combining the excellent photoelectric properties of perovskites and the remarkable gas-sensing properties of IGZO at room temperature, the devised sensors generate open-circuit voltage and modulate according to the ambient NO2 concentration. The major challenge in devising self-powered gas sensors is to attain harvesting capability and selectivity simultaneously, owing to perovskites reactivity in the presence of oxygen and humidity. In this work, we developed a novel approach and fabricated a heterojunction sensor using parylene-c as an additional layer to curb the cross-sensitivity and to enhance the selectivity of the sensor. Even under the low concentrations of NO2, the developed sensor exhibits remarkable sensitivity, selectivity, and repeatability. The devices are sensitive and robust even under extreme humidity conditions (80% RH) and synthetic air. The devised sensor configuration is one way to eliminate the cross-sensitivity issue of the perovskite-based devices and serves as a reference for the development of self-powered sensors.

It is of great significance to construct heterojunctions using industrially produced co-catalysts. The direct Z-scheme composite photocatalyst provides an effective separation of photogenerated carriers. Herein, a kind of novel 2D/3D direct Z-scheme NiFe-LDH/Zn0.5Cd0.5S is prepared. Compared with fresh catalysts, the NiFe-layered double hydroxide (LDH)/Zn0.5Cd0.5S composite exhibits advantages including excellent visible light response ability and photoelectric performance and improved H2 evolution rate by 11.6 times. Combining with theoretical calculations, ESR, XPS, and experimental results, the direct Z-scheme mechanism of the photocatalytic reaction is proposed. There is a channel for electron transfer between Zn0.5Cd0.5S and NiFe-LDH, and the electrons of Zn0.5Cd0.5S directly combine with the valence band holes of NiFe-LDH. Finally, the electrons remaining on NiFe-LDH can reduce H+ to generate H2. This process effectively achieves separation of photogenerated carriers and increases photocatalytic H2 evolution.

In recent years, transparent and flexible materials have been widely pursued in electronics and optoelectronics fields for usage as planar electrodes, energy conversion components and sensing units. As the most widely applied semiconductor material, the related progress in silicon is of great significance although with large difficulty. Herein, we report a one-step method to achieve flexible and transparent silicon nanowires aerogel membrane. A competitive carrier kinetics involving interfacial trapped carriers and the valence electrons transition is demonstrated, according to the photoelectric performance of a sandwiched graphene/silicon nanowires membrane/Al device, i.e., rapidly positive photoresponse dominated by laser excited free-carriers generation (∼ 500 ms) and subsequent slow negative photocurrent evolution due to laser heating involved multi-levels process (> 10 s). These results contribute to fabrication of silicon nanowire self-assembly structures and also the exploration of their optoelectrical properties in flexible and transparent devices.

The hybrid nanocrystals of zinc oxide (ZnO), cadmium oxide (CdO) and copper oxide (CuO) were self-assembled to the nanospheres with special structure in the process of inverse Pickering miniemulsio...

The photoelectric properties of thin films based on an organic composition of fullerene (C60), zinc phthalocyanine (ZnPc), and a ferroelectric copolymer of vinylidene fluoride with trifluoroethylene P(VDF–TrFE) are studied. Along with well-pronounced photoelectric properties (which are characteristic of fullerene–phthalocyanine mixtures), this material is shown to have ferroelectric properties as well. Ferroelectric switching of polarization is found to cause bistable switching of the photoelectric effect with a significant increase in the ampere–watt sensitivity in one of the polarized states. This effect is explained by a change in the built-in local electric field, which depends on the direction of the ferroelectric polarization vector and acts inside the cavities of the ZnPc/C60 molecular heterojunctions.

By using different transition metal ions three isostructural Anderson based compounds were obtained, [M2II(H3bdpm)2TeMo6O24(H2O)6] (M = Co (1); Cd (2); Zn (3)). Compounds 1-3 can act as photoelectr...

Low-dimensional organic-inorganic metal halides (OIMHs), as emerging light-emitting materials, have aroused widespread attention owing to their unique structural tunability and photoelectric characteristics. OIMHs are also promising materials for optoelectronic equipment, light-emitting diodes, and photodetectors. In this study, (C3H12N2)2Sb2Cl10 (C3H12N22+ is an N-methylethylenediamine cation), a new zero-dimensional OIMH, has been reported, and (C3H12N2)2Sb2Cl10 possesses a P21/n space group. The (C3H12N2)2Sb2Cl10 structure contains [Sb2Cl10]4- dimers (composed of two edge-sharing [SbCl6]3- octahedra) that are surrounded by C3H12N22+ cations. The experimental band gap of (C3H12N2)2Sb2Cl10 is 3.80 eV, and density functional theory calculation demonstrates that (C3H12N2)2Sb2Cl10 possesses a direct band gap, with the edge of the band gap mainly contributed from the inorganic units. (C3H12N2)2Sb2Cl10 exhibits good ambient and thermal stability. Under 395 nm excitation at room temperature, (C3H12N2)2Sb2Cl10 exhibits a broad emission with a full width at half-maximum of ∼114 nm, peaking at 480 nm, and the broad emission was ascribed to self-trapped exciton emission.

Two-dimensional organic-inorganic hybrid perovskites (OIHPs) have gained attention as a result of their flexibility and adjustability of the structure. However, the large band gap of two-dimensional perovskites limits their application in the photoelectric field. In the present work, we report a two-dimensional organic-inorganic hybrid compound of (C7H18N2)PbI4 (1) with a narrow band gap, which consists of [PbI4]2-n layers and N-(2-aminoethyl)piperidinium cations. 1 exhibits semiconducting properties with a narrow optical band gap of ∼2.02 eV and a photoelectric response with a ratio of photocurrent to dark current of ∼100. In addition, it exhibits a reversible solid-state phase transition at 228 K. This finding should inspire research into more 2D layered OIHPs with the combination of phase transition and semiconductor properties.

The photoelectric and optical characteristics of an organic solar cell (OSС) with a hole-transport layer based on a polyaniline complex and a photoactive layer with a bulk heterojunction based on P3HT polythiophene derivative and PC71BM fullerene have been studied. The results of modeling the optical properties of the functional layers and experimental measurements of the OSC characteristics enabled the optimal values of the thickness of the functional layers resulting in the maximum power conversion efficiency of the device to be identified. It has been determined that the hole-transport layer with a thickness of 30–60 nm, while having a transmission of more than 80%, effectively transferred holes to the photoanode from the photoactive layer, in which the exciton generation rate was 5.6–5.9 × 1016 cm–2 s–1. These values of the exciton generation rate at the maximum total light absorption in the device were provided by a photoactive layer with a thickness of 90–100 nm.

Intermolecular charge transfer (ICT) effect has been widely studied in both small molecules and linear polymers. Covalently-bonded donor-acceptor pairs with tunable bandgaps and photoelectric properties endow these materials with potential applications in optoelectronics, fluorescent bioimaging, and sensors, etc. However, owing to the lack of charge transfer pathway or effective separation of charge carriers, unfavorable charge recombination gives rise to inevitable energy loss. Covalent organic frameworks (COFs) can be mediated with various geometry- and property-tailored building blocks, where donor (D) and acceptor (A) segments are connected by covalent bonds and can be finely arranged to form highly ordered networks (namely D-A COFs). The unique structural features of D-A COFs render the formation of segregated D-A stacks, thus provides pathways and channels for effective charge carriers transport. This review highlights the significant progress on D-A COFs over the past decade with emphasis on design principles, growing structural diversities, and promising application potentials.

A sensitive photoelectrochemical biosensor was constructed for the detection of chlorpyrifos. The sensor was prepared on indium tin oxide (ITO) electrode using photoelectric material bismuth vanada...

Perovskite solar cells (PSCs) have become the promising next-generation photovoltaic devices due to their excellent photoelectric performances, and the power conversion efficiencies (PCEs) have experienced unprecedented rapid increase in recent years. However, to realize the practical application of PSCs, high performance and long-term stability are required and the preparation of high-quality perovskite film is the key. Herein, we adopt a simple and effective method to prepare high-quality perovskite films by introducing the poly(vinylidene fluoride) (PVDF) polymer additive with abundant hydrophobic F. As the growth template, the PVDF promotes the growth of perovskite crystal, improves the crystallinity and film morphology, thus reducing defect density and inhibiting carrier recombination. The results show that the photovoltaic performances of the perovskite device with PVDF are meaningfully improved, and a high PCE of 21.42% is achieved with an improvement of 10.87%. More importantly, the PVDF-based perovskites display greatly enhanced humidity and heat stability due to the protection of strong hydrophobic barrier from F and PVDF long chain. Aging at 45% ± 5% relative humidity (RH) for 2400 h and 85 °C for 300 h, respectively, the unsealed PVDF devices can maintain over 90% of the initial PCE. It indicates that suitable polymer additives can improve the film quality to acquire high-performance and stable PSCs and lay a foundation to design new perovskite light absorption layer with different polymers for the further development of PSCs.

Germanium selenide attracts emerging attention for applications in high-performance field-effect transistors and photodetector, due to its unique photoelectric performances and tunable bandgap. Herein, the germanium selenide-reduced graphene oxide (GeSe-RGO) hybrid is successfully synthesized by loading liquid-phase exfoliated GeSe nanosheets on the 2D graphene via a hydrothermal reduction process. It is demonstrated that the photoresponse performance of the photoelectrochemical (PEC) device constructed by the synthesized GeSe-RGO hybrid is significantly enhanced in comparison to the one built by the sole GeSe nanosheets. The results of the PEC tests display the photocurrent density can reach to 8.45 μA/cm2 at the bias of 0.8 V, which is approximately 4 times that of sole GeSe nanosheets. Meanwhile, with the increase of illumination intensity, the photocurrent density of the GeSe-RGO photodetector almost presents a linear increase. When the illumination intensity is 90 mW/cm2, the photoresponsivity value is up to 116 μA/W. In addition, the GeSe-RGO hybrid shows a durable photoresponse capability under the bias of 0 V, revealing that such a hybrid has the excellent self-powered ability in the PEC system. There is no evident degradation on the photoresponsive performance of GeSe-RGO photodetector after 50 light on-off cycling, indicating the good stability of the hybrids. The enhanced performance of the GeSe-RGO hybrid is attributed to the outstanding photoresponsive capability of RGO and the effective separation of photo-generated electron-hole pairs. Our work indicates that the GeSe-RGO hybrid has great prospects for future applications in PEC-type photodetector devices.

C3N4, C3N4@Ti3C2 and W18O49@C3N4@Ti3C2 hollow spheres were successfully prepared by using SiO2 template followed by gradual deposition method. The degradation of phenol solution and photolysis ability were tested to characterize its photocatalytic activity. Compared with the single-shelled C3N4 and C3N4@Ti3C2 hollow spheres, double-shelled W18O49@C3N4@Ti3C2 hollow spheres possessed larger surface area and fast charge separation efficiency, exhibiting about 8.9 times and 4.0 times higher H2 evolution than those of C3N4, C3N4@Ti3C2 hollow spheres, respectively. The photocatalytic mechanism of the W18O49@C3N4@Ti3C2 hollow spheres were carefully investigated according to the results of morphology design and photoelectric performance. A Z scheme mechanism based on the construction of heterojunctions was proposed to explain the improvement of photocatalytic performance. This new charge transfer mechanism appears to greatly inhibit the recombination of electrons/holes during the charge transfer process, while maintaining its strong hydrogen reduction ability, resulting in a higher photocatalytic performance.

Schottky barriers (SBs) based on gallium phosphide (GaP) attract researchers’ attention as promising structures for the development of various types of radiation-resistant electronic and photovoltaic devices, including high-temperature devices, high-frequency power electronics, ultraviolet (UV) photoelectronics and solar energy. This work studies photoelectric properties of surface-barrier (SB) structures of Au-palladium-n-GaP in the visible spectrum range under the action of both natural and polarized radiation, in order to obtain new data on the barrier height, band structure of GaP and the interface metal semiconductor.In particular, nanostructured Au-palladium-n-GaP structures were examined.The initial material for the structures production - n-GaP plates [n = (0.1-5) · 1017 cm-3, 300 K] with a thickness of 350-400 µm, oriented in the crystallographic plane (100), grown with the Czochralski method. Studying photosensitivity of nanostructured structures of the Au-Pd-n-GaP type in the visible spectrum range gives important information about the parameters of the potential barrier, the band structure of the semiconductor. Thus, the intermediate Pd (palladium) nanolayer between GaP and Au with a thickness of 20-30 A creates specific properties in the Au-Pd-n-GaP nanostructure that are of great scientific and practical importance.

High-Curie-temperature (Tc) ferroelectrics have exhibited broad applications in optoelectronic devices. Recently, two-dimensional multilayered perovskite ferroelectrics with excellent photoelectric attributes are attracting increasing interest as new systems of photoferroelectrics. However, the effective tuning of the Tc value of a multilayered perovskite photoferroelectric system still remains a huge challenge. Here, by a halogen substitution strategy to introduce bromine atoms on n-propylamine cations, the hybrid perovskite photoferroelectric (3-bromopropylaminium)2(formamidinium)Pb2Br7 (BFPB) with a high Tc value (348.5 K) was obtained. It is notable that BFPB adopts a two-dimensional bilayered inorganic framework, with tight linking to the organic cation by C-Br···Br-Pb halogen···halogen interactions and N-H···Br hydrogen bonds. Intriguingly, in comparison with the prototypical compound (n-propylaminium)2(formamidinium)Pb2Br7, a remarkable augmentation of 85.2 K in the resulting Tc value of BFPB is clearly observed, which further broadens the temperature range of its application. In combination with the remarkable ferroelectric and semiconducting attributes, the reversible bulk photovoltaic effect was realized in single crystals of BFPB. This finding can not only enhance the hybrid perovskite ferroelectric family but also further promote the photoelectric application of ferroelectrics.

A variety of organic semiconductor nanostructures have been already reported for photoelectric applications; however, there are a few systematic studies on the dependence of their photocurrent on n...

A study of the electrical and photoelectric properties of the heterostructure of barium strontium titanate film on a silicon substrate was performed. The conductivity of the heterostructure signifi...

Ternary metal halides are important photoelectric materials with proven high performance as absorber layers in solar cells. In this paper, we explore the crystal structures of the low-cost, nontoxi...

The advantages of organic–inorganic hybrid halide perovskites and related materials, such as high absorption coefficient, appropriate band gap, excellent carrier mobility, and long carrier life, provide the possibility for the preparation of low-cost and high-efficiency solar cell materials. Among the inorganic materials, CsPbI3 is paid more attention to by researchers as CsPbI3 has incomparable advantages. In this paper, based on density functional theory (DFT), we first analyze the crystal structure, electronic properties, and work function of two common bulk structures of CsPbI3 and their slices, and then, we study the carrier mobility, exciton binding energy, and light absorption coefficient. Considering that CsPbI3 contains heavy elements, the spin–orbit coupling (SOC) effect was also considered in the calculation. The highest mobility is that electrons of the cubic structure reach 1399 cm2 V–1 S–1 after considering the SOC effect, which is equal to that of traditional solar cells (such as Si-based, PbSe, and PbTe). The lowest exciton binding energy is 101 meV in the cubic bulk structure, which is beneficial to the separation of photogenerated carriers. In the visible region, the absorption coefficient of the cubic structure is the best among all structures, reaching 105 cm–1. Through the study of mobility, exciton binding energy, and light absorption coefficient, it is found that the cubic bulk structure in all structures of CsPbI3 has the best photoelectric performance. This paper can provide some guidance for the experimental preparation of CsPbI3 as a potential high-efficiency solar cell material.

Graphene has a unique regular hexagonal honeycomb carbon structure, which results in excellent photoelectric and chemical properties. Especially the plasmon coupling effect produced by the composit...

Enhancement of photoelectric properties related to surface chemistry states of composite oxide TiO2-SrTiO3 has attracted extensive interest over the past few years owing to its unique internal structure. In this paper, the composite oxide TiO2-SrTiO3 thin films have been successfully fabricated via sol-gel method. Various characterizations such as X-ray diffraction, field emission scanning electron microscope, and X-ray photo electron spectroscopy are utilized to investigate the crystal phase, surface morphology, and chemical compositions of the composite oxide TiO2-SrTiO3 thin film. By measuring the photoluminescence spectrum, we investigate the band gap and the electron transition. It is found that PL result is closely related to the information of charge carrier trapping. Current-voltage characteristics indicate that the TiO2-SrTiO3 has better photoelectric performance than that of pure strontium titanate and rutile titanium dioxide. Additionally, the composite oxide TiO2-SrTiO3 thin film shows favorable photoelectric response, high sensitivity, and good stabilization. First-principle calculation based upon the density functional theory (DFT) is the first time to explicate the energy band and state density of the composite oxide of the TiO2-SrTiO3 with the appropriate model. This study deepens understanding of the photoelectric properties and electron structure of the new composite oxide TiO2-SrTiO3 thin film, which is expected for further applications in optoelectronic devices. The composite oxide TiO2-SrTiO3 thin film device performs more better photoelectric activity than the pure SrTiO3 and TiO2 thin film devices. The short-circuit current (Isc) is 0.047 μA and the open-circuit voltage (Voc) is − 0.8 V.

Photoresponse ranges of commercially prevailing photoelectric semiconductors, typically Si and InGaAs, are far from fully covering the whole solar spectrum (∼295-2500 nm), resulting in insufficient solar energy conversion or narrow wave bands for photoelectric detection. Recent studies have shown that infinite π-aggregation of viologen radicals can provide semiconductors with a photoelectric response range covering the solar spectrum. However, controlled assembly of an infinite π-aggregate is still a great challenge in material design. Through directional self-assembly of electron-transfer photoactive polycyclic ligands, two crystalline inorganic-organic hybrid photochromic viologen-based bismuth halide semiconductors, ((Me)3pytpy)[BiCl6]·2H2O [1; (Me)3pytpy = N,N',N″-trimethyl-2,4,6-tris(4-pyridyl)pyridine] and ((Me)3pytpy)[Bi2Cl9]·H2O (2), have been synthesized. They represent the first series of pytpy-based photochromic compounds. After photoinduced coloration, the conductivities of both 1 and 2 increased. The radical products have electron absorption bands in the range of 200-1600 nm, exceeding that of Si. Both the conductivity and the photocurrent intensity of 2 are stronger than those of 1, due to better planarity, tighter π-stacking, and higher degrees of overlap of ((Me)3pytpy)3+ cations. This study not only provides a new design idea for synthesizing radical-based multispectral photoelectric semiconductors but also enriches the family of electron-transfer photochromic compounds.

Strain-adjusting the band gap of MoS2 using patterned substrates to improve the photoelectric performance of MoS2 has gradually become a research hotspot in recent years. However, there are still difficulties in obtaining high-quality two-dimensional materials and preparing photodetectors on patterned substrates. To overcome this, a continuous multilayer MoS2 film was transferred to a patterned gallium nitride substrate (PGS) for the fabrication of photodetectors, and density functional theory calculations showed that the band gap of the MoS2 film increased and that the electron effective mass decreased due to the introduction of PGS. In addition, finite difference time domain simulation showed that the electric field in the MoS2 area on the PGS is enhanced compared with that on the flat gallium nitride substrate due to the enhanced light scattering effect of the PGS. The photoresponse of the MoS2/PGS photodetector at 460 nm was also enhanced, with Iph increasing by 5 times, R increasing by 2 times, NEP decreasing to 3.88 × 10-13 W/Hz1/2, and D* increasing to 5.6 × 108 Jones. Our research has important guiding significance in adjusting the band gap of MoS2 and enhancing the photoelectric performance of MoS2 photodetectors.

Quyosh elementlarini turlari juda ko’p. Ular ichida eng keng tarqalgani kremniy asosli quyosh elementidir. Kremniy asosli quyosh elementini foydali ish koeffitsientini orttirish, uning xususiyatlarini to’liqroq o’rganish maqsadga muvofiq. Chunki kremniy dunyoda eng keng tarqalgan elementlardan biri. Ushbu ishda kremniy asosli quyosh elementini opto-elektrik xususiyatlariga nanozarrachalarining ta’sirini o’rganilgan. Bilamiz, yorug’lik tushish burchagi o’zgarishi bilan quyosh elementining fotoelektrik parametrlari o’zgaradi. Ushbu maqolada, oddiy va nanozarracha kiritilgan kremniy asosli quyosh elementlarining fotoelektrik parametrlariga yorug’lik tushish burchagining ta’siri o’rganilgan.

The photoelectric interconnection of matrix photodetectors in the medium-wave IR range of 320 × 256 elements with a step of 30 μm and 640 × 512 elements with a step of 15 μm based on indium antimonide is investigated. The dependence of the crosstalk value on the thickness of a thinned InSb bulk structure was determined. The interrelation of the elements of matrix photodetectors based on epitaxial indium antimonide is significantly less than the interrelation based on bulk indium antimonide.

Photoelectric dyes, which absorb light and generate electric potential, have been shown to stimulate retinal neurons. Therefore, in the present work, a photoelectric dye was used to develop a retinal prosthesis to restore vision loss due to diseases, such as retinitis pigmentosa. The retinal prosthesis, referred to as a dye-coupled film, was prepared by chemically coupling the dyes to a polyethylene film surface. However, the amount of coupled dye decreased during an implantation test in a monkey’s eye. The dye consisted of a cation with photoresponsivity and Br−. Because thermal stability can be improved by anion exchange, we expected anion exchange to lead to stabilization of the chemical structure, resulting in improvement of the long-term durability of a retinal prosthesis. Therefore, the effects of exchanging Br− anions for PF6−, BF4−, and bis(trifluoromethanesulfonyl)imide (TFSI−) anions on the durability were investigated. The long-term durability of the dye-coupled films was found to be strongly related to the thermal stability of the photoelectric dye. The long-term durability of the dye-coupled film–PF6− and dye-coupled film–TFSI− improved by 637 and 215%, respectively, compared with that of the dye-coupled film–Br−. Our retinal prosthesis, referred to as a dye-coupled film, was developed by chemically coupling photoelectric dyes to the surface of a polyethylene film for restoring retinitis pigmentosa. However, the amount of coupled dye decreased during an implantation test in a monkey’s eye. For improving long-term durability, anion exchange from Br− to PF6−, BF4−, and bis(trifluoromethanesulfonyl)imide (TFSI−) was conducted. The long-term durabilities of the dye-coupled film–PF6−, –TFSI−, and –BF4− improved by 637, 215, and 48%, respectively, indicating that the dye-coupled film–PF6− exhibits the best long-term durability.

Realizing nitrogen reduction reaction (NRR) to synthesis NH3 under mild conditions has gained extensive attention as a promising alternative way to the energy- and emission-intensive Haber–Bosch process. Among varieties of potential strategies, photoelectrochemical (PEC) NRR exhibits many advantages including utilization of solar energy, water (H2O) as the hydrogen source and ambient operation conditions. Herein, we have designed a solar-driven PEC-NRR system integrating high-efficiency Fe2O3-based photoanode and atomically dispersed cobalt (Co) cathode for ambient NH3 synthesis. Using such solar-driven PEC-NRR system, high-efficiency Fe2O3-based photoanode is responsible for H2O/OH− oxidation, and meanwhile the generated photoelectrons transfer to the single-atom Co cathode for the N2 reduction to NH3. As a result, this system can afford an NH3 yield rate of 1021.5 μg mgCo-1 h-1 and a faradic efficiency of 11.9% at an applied potential bias of 1.2 V (versus reversible hydrogen electrode) on photoanode in 0.2 mol/L NaOH electrolyte under simulated sunlight irradiation.

The techniques of melt-quenching were used to manufacture 53B2O3–2NaF–27PbO– $$(20-x)$$ BaO– $$x$$ La2O3 $$(0\le x \ge 15)$$ glass system. To check the status of these samples, the XRD diffractometer procedure was used. The molar volume of the glass system is decreased while density is increased. The current glass sample's mechanical properties depend on the glass structure. Ultrasonic velocity and elastic modulus (experimental and theoretical) of glass samples were observed to be increased. FT-IR analysis shows that with the increase of La2O3 increases the changes of BO3 to BO4 and increases the degree of glass connectivity and the structural units of (BO3/2 F)− tetrahedra are formed. It has been noted that the MAC values of glass samples are decreased to 1 meV, apart from a small increase at 0.1 meV. At low energy, this significant decline and small peak are directly linked to the current photoelectric effect. The sample with the highest La2O3 content is owned the MAC's greatest values. It has been noted that the (HVL) and (TVL) increase with the increase in the photon energy and La2O3 content rendering to the achieved results. It has been noted that the Zeff has the largest values at lower energy and at lowering concentration of La2O3 content. It has been noted that EABFs and EBFs have originally lower values at low energy levels, because the photoelectric effect dominates and BaO is replaced by La2O3.