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By comparing the results of calculations using the Mie theory, which is considered exact, a validity region of the approximate method for calculating the extinction cross section of spherical nanoparticles through polarizability has been found. The calculations were performed for w-CdS, InP, and PbS, and their results were presented in the form of the exact extinction cross section to the approximate absorption cross section ratio as a function of the particle size and light wavelength. The extinction coefficients for w-CdS and PbS nanoparticles depending on the wavelength and refractive index of the medium have also been calculated. [ABSTRACT FROM AUTHOR]

High-temperature colloidal synthesis was used to produce InP nanocrystals with a mean diameter of 2 nm covered with a thin ZnS shell and organic ligands ~1 nm in length. The addition of acetonitrile to a toluene solution of these nanoparticles led to the formation of aggregates with a hydrodynamic diameter of 0.2 μm. The aggregates were stable at acetonitrile/toluene ratios from 1/1 to at least 14/1. A close distance between nanocrystals in the aggregates enabled interparticle Förster resonance energy transfer. The addition of an excess of toluene to a solution of these aggregates promoted their disaggregation into individual InP/ZnS nanocrystals. [ABSTRACT FROM AUTHOR]

Understanding high‐order biexciton dynamics is important for the use of semiconductor quantum dots (QDs) in optoelectronic devices. The core–shell structure can be used to modulate biexciton dynamics by varying the shell thickness and core–shell energy band alignment. In this study, the biexciton dynamics in an unconventional case in which each QD is encapsulated by a submonolayer shell are demonstrated. The result of a transient absorption spectroscopic study shows that InP/ZnS core/shell QDs with submonolayer shell coverage exhibit a prolonged Auger lifetime. However, the QD size dependence of the Auger recombination time features two constant distinct stages instead of the typical monotonic volume scaling law in conventional QDs. It is attributed to the tradeoff between the enlarged QD size and quantum‐well confinement for the Auger processes. However, the abrupt change between the two stages is due to the change in the shell coverage. This study provides a reference for the application of core–shell QDs in optoelectronic devices in which full coverage of the shell is not achieved. [ABSTRACT FROM AUTHOR]

A novel broadband antenna designed for the terahertz (THz) frequency range is proposed and developed for the THz emitter on a photomixer chip. This THz emitter comprises an ultra-high-speed indium phosphide photodetector integrated with a planar THz antenna. This paper presents a novel broadband antenna configuration comprising a combination of bowtie and circular patch elements designed for the frequency range of 150 GHz to 500 GHz. Detailed parametric analysis of the antenna's design parameters is also provided. The simulation results demonstrate that the optimized antenna achieves an impedance bandwidth of 350 GHz, satisfying the |S11| ≤ −10 dB condition, and exhibits a relative bandwidth of 107% within the 150 GHz to 500 GHz frequency range. This novel broadband terahertz antenna showcases an exceptional wideband performance and is highly suitable for high-speed transmission systems. [ABSTRACT FROM AUTHOR]

Indium, a rare metal, is created incidentally during the zinc refining process. When a zinc metal is produced, valuable elements, such as indium, are recovered and reused. The sulfide minerals, sphalerite, galena, and chalcopyrite, are all common hosts for indium metals. Indium metals of varying purities (from 99% to 99.9%) are used in many different commercial, other exclusive, specialty, dentistry, and research and development settings. In the production of indium phosphide and related select bulk single crystals, such as InP, InAs, InSb, etc., and select multilayered epitaxial material-systems based device structures, such as InGaAs/InP, InGaAsP/InP, etc., an ultrahigh purity (99.99999%) indium metal is used as one of the initial and primary input materials. light-emitting diodes, infrared detectors, lasers, and other components cannot be made without these device topologies. Triple junction solar cells made of GaInP, GaAs, and Ge with 40% conversion efficiency are being developed for use in space. Metal-organic and molecular beam epitaxial methods utilize trimethyl/triethyl-indium-epi-precursors, the high purity indium derivatives, as starting materials to develop and manufacture multilayered structures of InGaAs/InP, InGaAsP/InP, InGaN/InP AlInN, etc. The purpose of this review is to quickly touch on indium mineral sources, important uses for different indium metal grades, and the processes needed to refine, purify, and ultrahigh purify indium to higher purity levels using a zone refining–melting–leveling process, as well as impurity segregation considerations. The use of vacuum, inert gas environments, and an external electromagnetic field to efficiently segregate, levitate, stir, homogenize, and mix the molten zone/melt interface area (region) as well as purity analyses at ppb levels, class clean room, and packaging concepts were also discussed. This review also touched briefly on the use of ultrahigh purity indium in the preparation of TMIn, TEIn, and InCl precursors necessary for the growth of device structures by molecular beam, metal-organic vapor phase, atomic layer epitaxial, and chemical vapor deposition processes. Purifying and preparing polycrystalline indium to a type 7 N purity level as well as standardization and criticality testing for fine-tuning system parameters are essential parts of developing the purification process technology. It also highlights various compound semiconductors and epitaxial systems, such as high purity indium compounds, such as indium phosphide, for cutting-edge electronic applications. Material yield enhancement, impurity management (including C, O, N, and others), consistent results, impurity reduction (down to the ppb level), and class clean packaging are all active topics of research and development. There has been a rise in demand for ultrapure metals (7–10 N) with stringent purity criteria in the aerospace and defense sectors, where they are used in cutting-edge nanoelectronic applications. This literature review delves into these and related topics regarding the production of ultrahigh purity indium. The major objective of this review is to provide a concise summary of the research and development progress made toward the ultrahigh purity (7N-99.99999%) indium preparation and its epitaxial electronics application considerations as of the time of this writing. [ABSTRACT FROM AUTHOR]

In this paper, the reliability of InP/InGaAs DHBTs under high reverse base–collector bias stress is analyzed by experiments and simulation. The DC characteristics and S parameters of the devices under different stress times were measured, and the key parameters with high field stress were also extracted to fully understand and analyze the high-field degradation mechanism of devices. The measurements indicate that the high-field stress leads to an increase in base current, an increase in base–collector (B–C) and base–emitter (B–E) junction leakage current, and a decrease in current gain, and different degrees of degradation of key parameters over stress time. The analysis reveals that the degradation caused by reverse high-field stress mainly occurs in the B–C junction, access resistance degradation, and passivation layer. The physical origins of these failure mechanisms have been studied based on TCAD simulation, and a physical model is proposed to explain the experimental results. [ABSTRACT FROM AUTHOR]

Quantum dots (QDs) are promising semiconductor nanocrystals in photocatalysis due to their unique properties and in contrast to bulk semiconductors. Different from the traditional modification methods of indium phosphide (InP) QDs such as metal doping, shell design, and surface ligand modification, we firstly constructed the indium phosphide quantum dot and carbon quantum dot (InP QDs/CQDs) system and used it for the study of photocatalytic hydrogen production from hydrogen sulfide (H2S) in this work. The photocatalytic performance tests show that the average rate of photocatalytic decomposition of hydrogen sulfide to produce hydrogen of the InP QDs/CQDs system increases by 2.1 times in contrast to InP QDs alone. The steady-state and time-resolved photoluminescence spectra demonstrated that the introduction of CQDs can effectively improve the separation efficiency of photo-generated carriers. In addition, the surface electronegativity of the InP QDs/CQDs system is weaker than that of InP QDs, which may reduce the repulsion between the photocatalyst and reaction substrate, promoting the surface oxidation reaction in the photocatalytic process. This work indicates that the construction of the QDs hybrid system can improve their photocatalytic performance, providing a way to optimize QDs in photocatalysis. [ABSTRACT FROM AUTHOR]

Indium phosphide (InP) quantum‐dot light‐emitting diodes (QLEDs) are considered as one of the most promising candidates for emerging displays owing to their good luminous performance and environmentally friendly properties. The operation of green InP QLEDs relies on the radiative recombination of electrically generated excitons, as in most QLEDs; however, the electrons injected into green InP QLEDs can easily pass through the quantum‐dot (QD) layer, resulting in a carrier imbalance and low external quantum efficiency (EQE). Herein, the mechanism of electron leakage in green InP QLEDs is revealed. Based on comparative experiments and simulations of the carrier concentration distribution, the path of electron leakage is determined and it is found that the root cause is the large Fermi energy difference between green InP QDs and indium tin oxide (ITO). To solve this problem, an ultrathin LiF layer is applied to modify the work function of the ITO, which simultaneously hinders electron leakage and enhances hole injection. Benefiting from a more balanced carrier injection, the maximum EQE of green InP QLEDs improves from 4.70% to 9.14%. In these findings, a universal mechanism is provided for hindering electron leakage in green InP QLEDs, indicating the feasibility of developing highly efficient green InP QLEDs. [ABSTRACT FROM AUTHOR]

Integrated optics is a field of study and technology that focuses on the design, fabrication, and application of optical devices and systems using integrated circuit technology. It involves the integration of various optical components, such as waveguides, couplers, modulators, detectors, and lasers, into a single substrate. One of the key advantages of integrated optics is its compatibility with electronic integrated circuits. This compatibility enables seamless integration of optical and electronic functionalities onto the same chip, allowing efficient data transfer between optical and electronic domains. This synergy is crucial for applications such as optical interconnects in high-speed communication systems, optical sensing interfaces, and optoelectronic integrated circuits. This entry presents a brief study on some of the widely used and commercially available optical platforms and fabrication methods that can be used to create photonic integrated circuits.

This work highlights the novel approach of incorporating potassium iodide (KI) doping during the synthesis of In0.53P0.47 core quantum dots (QDs) to significantly reduce the concentration of vacancies (i.e., In vacancies; VIn−) within the bulk of the core QD and inhibit the formation of InPOx at the core QD–Zn0.6Se0.4 shell interfaces. The photoluminescence quantum yield (PLQY) of ~97% and full width at half maximum (FWHM) of ~40 nm were achieved for In0.53P0.47/Zn0.6Se0.4/Zn0.6Se0.1S0.3/Zn0.5S0.5 core/multi-shell QDs emitting red light, which is essential for a quantum-dot organic light-emitting diode (QD-OLED) without red, green, and blue crosstalk. KI doping eliminated VIn− in the core QD bulk by forming K+-VIn− substitutes and effectively inhibited the formation of InPO4(H2O)2 at the core QD–Zn0.6Se0.4 shell interface through the passivation of phosphorus (P)-dangling bonds by P-I bonds. The elimination of vacancies in the core QD bulk was evidenced by the decreased relative intensity of non-radiative unpaired electrons, measured by electron spin resonance (ESR). Additionally, the inhibition of InPO4(H2O)2 formation at the core QD and shell interface was confirmed by the absence of the {210} X-ray diffraction (XRD) peak intensity for the core/multi-shell QDs. By finely tuning the doping concentration, the optimal level was achieved, ensuring maximum K-VIn− substitution, minimal K+ and I− interstitials, and maximum P-dangling bond passivation. This resulted in the smallest core QD diameter distribution and maximized optical properties. Consequently, the maximum PLQY (~97%) and minimum FWHM (~40 nm) were observed at 3% KI doping. Furthermore, the color gamut of a QD-OLED display using R-, G-, and B-QD functional color filters (i.e., ~131.1%@NTSC and ~98.2@Rec.2020) provided a nearly perfect color representation, where red-light-emitting KI-doped QDs were applied.

Abstract Understanding high‐order biexciton dynamics is important for the use of semiconductor quantum dots (QDs) in optoelectronic devices. The core–shell structure can be used to modulate biexciton dynamics by varying the shell thickness and core–shell energy band alignment. In this study, the biexciton dynamics in an unconventional case in which each QD is encapsulated by a submonolayer shell are demonstrated. The result of a transient absorption spectroscopic study shows that InP/ZnS core/shell QDs with submonolayer shell coverage exhibit a prolonged Auger lifetime. However, the QD size dependence of the Auger recombination time features two constant distinct stages instead of the typical monotonic volume scaling law in conventional QDs. It is attributed to the tradeoff between the enlarged QD size and quantum‐well confinement for the Auger processes. However, the abrupt change between the two stages is due to the change in the shell coverage. This study provides a reference for the application of core–shell QDs in optoelectronic devices in which full coverage of the shell is not achieved.

Indium phosphide (InP) quantum‐dot light‐emitting diodes (QLEDs) are considered as one of the most promising candidates for emerging displays owing to their good luminous performance and environmentally friendly properties. The operation of green InP QLEDs relies on the radiative recombination of electrically generated excitons, as in most QLEDs; however, the electrons injected into green InP QLEDs can easily pass through the quantum‐dot (QD) layer, resulting in a carrier imbalance and low external quantum efficiency (EQE). Herein, the mechanism of electron leakage in green InP QLEDs is revealed. Based on comparative experiments and simulations of the carrier concentration distribution, the path of electron leakage is determined and it is found that the root cause is the large Fermi energy difference between green InP QDs and indium tin oxide (ITO). To solve this problem, an ultrathin LiF layer is applied to modify the work function of the ITO, which simultaneously hinders electron leakage and enhances hole injection. Benefiting from a more balanced carrier injection, the maximum EQE of green InP QLEDs improves from 4.70% to 9.14%. In these findings, a universal mechanism is provided for hindering electron leakage in green InP QLEDs, indicating the feasibility of developing highly efficient green InP QLEDs.

To scale up Indium phosphide (InP) crystal growth to industrial scale, there is a need to increase the growth rate and crystal length while maintaining high quality. Here, melt-conditioned vertical gradient freeze (MCVGF) is investigated. In this method, a pyrolytic boron nitride (PBN) rotor with special shape rotates inside the melt at a slow speed. It consequently enhances the melt movement and latent heat removal from the crystal front. In this study, a full 3-dimensional model is presented for both original and proposed VGF process including an energy equation, Navier–Stokes equations, moving mesh theory, and thermal stress equations. The growth speed is set to about 7 mm/h. Melt flow, temperature gradient, crystal front, and thermal stress were calculated and compared between these two cases. Crystal growth with acceptable quality is impossible during the original VGF process, but the MCVGF shows very good potential to overcome the limitations. The crystal front is found to be flat with small concavity at high growth rates, which is perfect for crystal growth. The thermal stress was checked for MCVGF: It reduces by 50% in comparison with original process under critical value. The simulation proved that MCVGF is feasible for the crystal growth process and is a perfect method for industrial crystal growers to increase production speed and crystal structural perfection. [ABSTRACT FROM AUTHOR]

Biomanufacturing of ethylene is particularly important for modern society. Cyanobacterial cells are able to photosynthesize various valuable chemicals. A promising platform for next‐generation biomanufacturing, the semiconductor‐cyanobacterial hybrid systems are capable of enhancing the solar‐to‐chemical conversion efficiency. Herein, the native ethylene‐producing capability of a filamentous cyanobacterium Nostoc sphaeroides is confirmed experimentally. The self‐assembly characteristic of N. sphaeroides is exploited to facilitate its interaction with InP nanomaterial, and the resulting biohybrid system gave rise to further elevated photosynthetic ethylene production. Based on chlorophyll fluorescence measurement and metabolic analysis, the InP nanomaterial‐augmented photosystem I activity and enhanced ethylene production metabolism of biohybrid cells are confirmed, the mechanism underlying the material‐cell energy transduction as well as nanomaterial‐modulated photosynthetic light and dark reactions are established. This work not only demonstrates the potential application of semiconductor‐N. sphaeroides biohybrid system as a good platform for sustainable ethylene production but also provides an important reference for future studies to construct and optimize nano‐cell biohybrid systems for efficient solar‐driven valuable chemical production. [ABSTRACT FROM AUTHOR]

ZnMgO nanoparticles (NPs) are commonly used as the electron transport layer (ETL) in indium phosphide (InP) based quantum dots light‐emitting diodes (QLEDs). It has been experimentally found that the inherent oxygen vacancy defects in ZnMgO can be passivated by halogen additives. However, an in‐depth understanding of how the halogen additives in ZnMgO affect the quantum dots (QDs) films is currently missing. Here, the study reports on efficient and stable indium phosphide (InP) green QLEDs by effectively bridging QDs and ETL using chloride (Cl) ions. As bi‐functional anchoring additives, Cl ions not only passivate the oxygen vacancy defects of ZnMgO NPs for suppressing the exciton quenching at the QDs/ZnMgO interfaces, but also facilitate the hole transport of QDs due to part replacement of insulated oleic acid ligands on the surfaces of InP QDs with Cl anions for more balanced charge injection in the devices. Consequently, the optimized green InP QLED achieves a peak external quantum efficiency (EQE) of 13.8% and an operational lifetime of 5944 h, which, to the best of current knowledge, represents the best overall performance among the reported green InP QLEDs. [ABSTRACT FROM AUTHOR]

The results of studies of 7.5–8.0 μm range surface-emitting ring quantum-cascade lasers are presented. A second- order diffraction grating with a calculated coupling coefficient of ~9 cm–1 is formed on the entire surface of the ring cavity by focused ion beam milling. Surface-emitting lasing at room temperature near 7.75 μm with a threshold current density of ~8 kA/cm2 and an outer radius of the ring cavity of 202 μm is demonstrated. The results of studying the intensity distribution in the far-field near the normal to the surface showed the presence of two maxima. It is shown that the implemented coupling coefficient is not sufficient to ensure single-mode lasing in the studied ring quantum-cascade lasers. [ABSTRACT FROM AUTHOR]

Quantum photonic technologies, such as quantum key distribution, are already benefiting greatly from the rise of integrated photonics. However, the flexibility in design of these systems is often restricted by the properties of the integration material platforms. Here, we overcome this choice by using hybrid integration of ultra-low-loss silicon nitride waveguides with indium phosphide electro-optic modulators to produce high-performance quantum key distribution transceiver chips. Access to the best properties of both materials allows us to achieve active encoding and decoding of photonic qubits on-chip at GHz speeds and with sub-1% quantum bit error rates over long fibre distances. We demonstrate bidirectional secure bit rates of 1.82 Mbps over 10 dB channel attenuation and positive secure key rates out to 250 km of fibre. The results support the imminent utility of hybrid integration for quantum photonic circuits and the wider field of photonics. [ABSTRACT FROM AUTHOR]

Definition: Integrated optics is a field of study and technology that focuses on the design, fabrication, and application of optical devices and systems using integrated circuit technology. It involves the integration of various optical components, such as waveguides, couplers, modulators, detectors, and lasers, into a single substrate. One of the key advantages of integrated optics is its compatibility with electronic integrated circuits. This compatibility enables seamless integration of optical and electronic functionalities onto the same chip, allowing efficient data transfer between optical and electronic domains. This synergy is crucial for applications such as optical interconnects in high-speed communication systems, optical sensing interfaces, and optoelectronic integrated circuits. This entry presents a brief study on some of the widely used and commercially available optical platforms and fabrication methods that can be used to create photonic integrated circuits. [ABSTRACT FROM AUTHOR]

The results of studies of ring quantum-cascade lasers with surface emission due to a second-order grating formed in the top cladding layers are presented. Surface emission near 7.85 μm with a low threshold current density (3.8 kA/cm2), in comparison with ridge quantum-cascade lasers of the same cavity length is demonstrated. The results of measurements of the intensity distribution of the near and far fields at different pumping levels are presented. The estimated value of the angle of beam extraction relative to the surface normal is in the range 5.7°–6.7°. [ABSTRACT FROM AUTHOR]

This paper presents a novel periodic grounded coplanar waveguide (GCPW) leaky-wave antenna implemented in an Indium Phosphide (InP) process. The antenna is designed to operate in the 220 GHz–325 GHz frequency range, with the goal of integrating it with an InP uni-traveling-carrier photodiode to realize a wireless transmitter module. Future wireless communication systems must deliver a high data rate to multiple users in different locations. Therefore, wireless transmitters need to have a broadband nature, high gain, and beam-steering capability. Leaky-wave antennas offer a simple and cost-effective way to achieve beam-steering by sweeping frequency in the THz range. In this paper, the first periodic GCPW leaky-wave antenna in the 220 GHz–325 GHz frequency range is demonstrated. The antenna design is based on a novel GCPW leaky-wave unit cell (UC) that incorporates mirrored L-slots in the lateral ground planes. These mirrored L-slots effectively mitigate the open stopband phenomenon of a periodic leaky-wave antenna. The leakage rate, phase constant, and Bloch impedance of the novel GCPW leaky-wave UC are analyzed using Floquet's theory. After optimizing the UC, a periodic GCPW leaky-wave antenna is constructed by cascading 16 UCs. Electromagnetic simulation results of the leaky-wave antenna are compared with an ideal model derived from a single UC. The two design approaches show excellent agreement in terms of their reflection coefficient and beam-steering range. Therefore, the ideal model presented in this paper demonstrates, for the first time, a rapid method for developing periodic leaky-wave antennas. To validate the simulation results, probe-based antenna measurements are conducted, showing close agreement in terms of the reflection coefficient, peak antenna gain, beam-steering angle, and far-field radiation patterns. The periodic GCPW leaky-wave antenna presented in this paper exhibits a high gain of up to 13.5 dBi and a wide beam-steering range from − 60 ° to 35 ° over the 220 GHz–325 GHz frequency range. [ABSTRACT FROM AUTHOR]

This study presents the physical properties of fluorescent material-doped E7 nematic liquid crystals (NLC). Indium phosphide/zinc sulfide (InP/ZnS) quantum dots and rubrene dye were preferred as fluorescent materials. In order to examine the effect of different fluorescent materials on the physical properties of E7 NLC, the phase transition temperatures, wavelength-dependent absorbance values, and the electro-optical and dielectric parameters of composites were determined. The obtained results showed that both InP/ZnS quantum dots and rubrene dye change the electro-optical and dielectric properties of E7 NLC. According to this, it is thought that fluorescent material-doped NLC composites could become a focus of interest for future electro-optical device applications. [ABSTRACT FROM AUTHOR]

We have obtained unique periodic oxide nanocrystallites on the surface of indium phosphide. The morphological characteristics of the structures obtained and their component composition are investigated in the article. The main attention is focused on explaining the mechanism of the periodic structures, which are packed by the ‘parquet floor’ type. The mechanism based on sliding the sources of rectangular-shaped dislocation loops has been proposed. The system of the main and secondary (ingoing) dislocations that cause the formation of the steps has been considered. The mathematical interpretation of the described model has also been proposed.

In this work, Monte Carlo simulation is performed for InP Gunn diode with a notch-d-doped structure. It is found that the presence of the d-doped layer has improved the Gunn diode performance significantly as compared to the conventional notch structure. The d-doped effect caused an increment in the fundamental operating frequency and current harmonic amplitude in InP Gunn diodes by modifying the electric field profile within the device. An InP notch-d-doped Gunn diode with device length of 800 nm under 3V DC bias is capable of producing AC current signal of 287 GHz, reaching the THz region, with its harmonic amplitude being 5.68×108 A/m2. It is observed that InP-based notch-d-doped Gunn diode is able to generate signals at a higher operating frequency with a larger output power as compared to that of GaAs due to the higher electron drift velocity and threshold field in InP material.

Asymmetric Mach-Zehnder interferometers (AMZIs) can, in principle, enable continuous wavelength tuning of a laser when used as intra-cavity filters. Their simplicity and good compatibility with generic foundry platforms are major advantages. However, the difficulty to develop a well-defined and robust control strategy is an important drawback which restricts the use-cases of these tunable lasers. Here, we make an in-depth investigation of the tunability properties of a laser including a single-stage AMZI in its cavity. We find that due to imperfections of Electro-Optic Phase Modulators (EOPMs), the dependence of the phase variation with the applied voltage is not linear. Because integrated EOPMs cannot be individually calibrated, these nonlinearities prevent a precise and independent tuning of the phase and amplitude of the AMZI transfer function, and thus continuous tuning cannot be reliably achieved. To overcome this issue, we propose a refined control strategy which allows for semi-continuous tuning. With this approach, we demonstrate a piece-wise continuous tuning of the emission wavelength by taking advantage of the coupling between amplitude and phase in the AMZI response. With our refined control strategy, we achieve tuning of the emission wavelength over the full free spectral range (FSR) of the AMZI.

New requirements for high-frequency applications in wireless communication and sensor technologies need III-V compound semiconductors such as indium phosphide (InP) to complement silicon (Si)-based technologies. This study establishes the basis for a new approach to heterogeneous integration of III-V on Si aimed at the transfer of single-crystalline InP coupons on Si via micro-transfer printing (μTP). The InP coupons will act as high-quality virtual substrates that allow selective homo-epitaxy. We present the chemical-mechanical polishing-based preparation and structural characterization of µm-thin (001) InP platelets, starting from high-quality 4-inch bulk crystals and micro-patterning into transferable coupons of several hundred µm2. The obtained InP platelets exhibit the desired thickness—below 10 ± 1 µm—and low surface roughness—<0.3 nm—on both sides, meeting the precondition for µTP and epitaxy. X-ray rocking curve measurements provide accurate spatial maps of the total strain, which indicate small strain variations in the µm-thin InP sample. Rocking curve mappings of the (0 0 4) reflection reveal half-widths below 16 arcsec in the majority of the sample area after thinning that is similar to commercially available InP bulk substrates. Pole figure measurements show no evidence of stress-induced micro-twinning or stacking faults. Overall, minor indications of crystal quality degradation in the product platelets, compared with the bulk samples, were detected. [ABSTRACT FROM AUTHOR]

The possibility of controlling the composition of lateral nanowires by the method of growth under quasi-equilibrium conditions in a quasi-closed volume from indium, phosphorus, and arsenic vapors with Au catalyst in the "vapor-liquid-solid" mechanism has been demonstrated for the first time. It has been experimentally shown that the additional presence of arsenic in the indium-phosphorus source leads to the coalescence of catalytic gold droplets at the initial stage of the growth, which determines the further morphology and growth kinetics of nanostructures. An additional formation of indium phosphide nanostructures with a composition different from that of the main nanowires was found. The results of the studies expand the possibilities of the developed method for obtaining lateral nanowires on gallium arsenide substrates. [ABSTRACT FROM AUTHOR]

[Display omitted] • 4-terminal III-V//c-Si multijunction device with a TOPCon bottom cell. • Wide-gap poly-SiO x as back surface field for TOPCon device. • Bifacial illumination of the 4-terminal device is examined. • Over 34% of cell efficiency with extra 0.25-sun illumination at the back. We propose a structural innovation for a four-terminal III-V//crystalline silicon (c-Si) multijunction (MJ) device under bifacial illumination. The top cell is a double-junction gallium indium phosphide (GaInP)/gallium arsenide (GaAs) cell structure, and the bottom cell is a tunnel oxide passivating contact (TOPCon) structure with a boron-diffusion emitter and a wide-gap polysilicon oxide (poly-SiO x) passivating rear contact. To maximise the albedo-reflectance light transmitted into the c-Si absorber, the wide-gap poly-SiO x passivating contact is intended to replace the conventional narrow-gap polysilicon (poly-Si) passivating contact at the rear of the TOPCon. With an extra 0.25-sun illuminated light at the back, the bottom cell's conversion performance improves by 14.5%. When compared to mono-illumination, bifacial illumination increases the overall efficiency of the MJ device by 2.67%. The design shows great potential for enhancing further the conversion performance of the bifacial GaInP/GaAs//TOPCon MJ devices using the wide-gap poly-SiO x passivating rear contacts. [ABSTRACT FROM AUTHOR]

This work reviews the design and applicability of beam-forming networks based on Coherently Radiating Periodic Structures (CORPS-BFN) at Terahertz (THz) frequency bands. These versatile networks offer two operation modes: a continuous beam steering – feeding an antenna array with a linearly progressive phase distribution – using a reduced number of phase controls; or a multi-beam operation, generating independent, overlapped beams. These networks are built upon the concatenation of power combiners/dividers (PCDs) with isolated outputs. The isolation is provided by monolithically integrated resistors, implemented with Ti/TiO 2 thin films for the first time. In this work, a planar prototype of a 2 × 3 (inputs/outputs) microstrip CORPS-BFN for operation in the WR3.4/WM-864 band (220–330 GHz) on a thin 50 μ m Indium Phosphide (InP) substrate is designed, fabricated, and characterized. The measured S-parameters show a reflection coefficient better than -15 dB and an insertion loss between 1.6 and 3.2 dB in the whole band. In addition, an isolation better than 20 dB between the input ports has been measured. An overall remarkable agreement is observed between the measurements and the simulations. Last, the applications, scalability and efficiency of this type of networks at the targeted band are discussed in detail. [ABSTRACT FROM AUTHOR]

In this research, ab initio investigation on the electronic, magnetic, and structural properties of 3d transition-metal (TM) impurities (Cu, Ni, Co, Fe, Mn, Cr, and V) doped armchair (5, 5) indium phosphide nanotubes (InPNT) was performed by using a density functional theory. The observations illustrate that there exists a structural distortion around 3d TM impurities with regard to the pure InPNT. Furthermore, the observations revealed that the total magnetic moment changes are in good agreement with Hund's rule. In addition, the Mn-doped InPNT has a maximum magnetic moment. The calculations exhibited that the InP nanotube is semiconductor in nature with a direct band gap of 1.46 eV. Also, the simulation results illustrated that when 3d TM impurities, except Cu, are replaced with In atom in InPNT, impurity doping leads to the magnetic form of the nanotube. Cu-doped InPNT is a non-magnetic metal whereas, Ni and Fe-doped InPNTs are ferromagnetic metals. The V-doped InPNT is also a magnetic semiconductor according to simulation data. Furthermore, we found that the Cr, Co, and Mn-doped InPNT are half-metals with 100% spin-polarization characters. This fact makes the InPNT used for Nano magnet and spintronic applications. In the end, our results show that the InP nanotube doped with iron is more stable than others. [ABSTRACT FROM AUTHOR]

Recently, single‐crystalline indium phosphide (InP) tetrapods, which allow an exciton to act in a true tetrapodal geometry, were successfully synthesized and proved as a useful platform to study multiple exciton behaviors. We used ZnCl2 precursor, a commonly used additive in the synthesis of aminophosphine‐based InP nanocrystals to enhance the optical performance, and successfully synthesized InP tetrapods (InP‐ZnCl2) with the narrower arm length distribution. Interestingly, no distinct enhancement in photoluminescence was observed while the arm length of the InP tetrapod was suppressed with the addition of ZnCl2. Further shell growth on InP‐ZnCl2 successfully preserved tetrapodal geometry in InP‐ZnCl2/ZnSe and showed higher photoluminescence than that of tetrapodal InP/ZnSe. The crystal structure of InP‐ZnCl2 was also retained even along with various Zn feed ratios as observed in x‐ray diffraction (XRD) patterns and showed no peak shift as Zn only passivates the surface of InP tetrapods. These results provide a platform to study the role of Zn precursor. [ABSTRACT FROM AUTHOR]

Recently, single‐crystalline indium phosphide (InP) tetrapods, which allow an exciton to act in a true tetrapodal geometry, were successfully synthesized and proved as a useful platform to study multiple exciton behaviors. We used ZnCl2 precursor, a commonly used additive in the synthesis of aminophosphine‐based InP nanocrystals to enhance the optical performance, and successfully synthesized InP tetrapods (InP‐ZnCl2) with the narrower arm length distribution. Interestingly, no distinct enhancement in photoluminescence was observed while the arm length of the InP tetrapod was suppressed with the addition of ZnCl2. Further shell growth on InP‐ZnCl2 successfully preserved tetrapodal geometry in InP‐ZnCl2/ZnSe and showed higher photoluminescence than that of tetrapodal InP/ZnSe. The crystal structure of InP‐ZnCl2 was also retained even along with various Zn feed ratios as observed in x‐ray diffraction (XRD) patterns and showed no peak shift as Zn only passivates the surface of InP tetrapods. These results provide a platform to study the role of Zn precursor. [ABSTRACT FROM AUTHOR]

Balanced charge injection into the emissive layer is a prerequisite for achieving highly efficient quantum dot light‐emitting diodes (QLEDs). The similar energy distribution of charge transport layers and indium phosphide (InP) quantum dots (QDs) facilitates excess electron injection to the InP QD layer. In this study, magnesium‐doped ZnO nanoparticles (ZMO NPs) are modified to suppress the electron injection to the InP QD layer. Particularly, hydroxyl groups are effectively replaced by electrically stable states through the passivation of ZMO NPs, retarding electron injection through the ZMO NP layer. The modified ZMO‐NP‐based InP QLEDs exhibit a maximum external quantum efficiency of 9.6% with a substantially enhanced operational lifetime compared with that of devices made with unmodified ZMO NPs. [ABSTRACT FROM AUTHOR]

As the commercial display market grows, the demand for low-toxicity, highly emissive, and size-tunable semiconducting nanoparticles has increased. Indium phosphide quantum dots represent a promising solution to these challenges; unfortunately, they typically suffer from low inherent emissivity resulting from charge carrier trapping. Strategies to improve the emissive characteristics of indium phosphide often involve zinc incorporation into or onto the core itself and the fabrication of core/shell heterostructures. InP clusters are high fidelity platforms for studying processes such as cation exchange and surface doping with exogenous ions since these clusters are used as single-source precursors for quantum dot synthesis. Here, we examined the incorporation of zinc and gallium ions in InP clusters and the use of the resultant doped clusters as single-source precursors to emissive heterostructured nanoparticles. Zinc ions were observed to readily react with InP clusters, resulting in partial cation exchange, whereas gallium resisted cluster incorporation. Zinc-doped clusters effectively converted to emissive nanoparticles, with quantum yields strongly correlated with zinc content. On the other hand, gallium-doped clusters failed to demonstrate improvements in quantum dot emission. These results indicate stark differences in the mechanisms associated with aliovalent and isovalent doping and provide insight into the use of doped clusters to make emissive quantum dots. [ABSTRACT FROM AUTHOR]

The addition of zinc complexes to the syntheses of indium phosphide nanocrystals (InP NCs) has become commonplace, due to their ability to alter and significantly improve observed optical properties. In this paper, the role of zinc complexes on the synthesis and observed properties of InP is carefully examined. Produced InP and InP:Zn2+ NCs are thoroughly characterized from both structural (core and surface) and optical perspectives over a wide range of Zn2+ compositions (0%–43% atomic content). We find no differences in the physical (NC size and polydispersity) and structural properties (crystallographic phase) of InP and InP:Zn2+ NCs. Optically, significant changes are observed when zinc is added to InP syntheses, including blueshifted absorption edges and maxima, increased quantum yields, and the near elimination of surface state emission. These improved optical properties result from surface passivation by zinc carboxylate moieties. Changes to the optical properties begin at zinc concentrations as low as 5%, demonstrating the high sensitivity of InP optical properties to exogenous species. [ABSTRACT FROM AUTHOR]

Multiple instability was found on the volt–ampere characteristic of the palladium-surface-oxidized indium phosphide structure. The effect is recorded when recording the dependence of differential conductivity and differential capacitance on the applied external voltage. A mechanism for the appearance of instabilities is proposed. [ABSTRACT FROM AUTHOR]

Fabricating a pit array on the surface of indium phosphide wafer can change its photoelectric properties, improve its photoelectric conversion efficiency, and expand its application range. There are few reviews devoted to the fabrication of regular hole arrays on the surface of indium phosphide wafers by electrochemical methods. In this paper, twelve electrochemical approaches for assembling pit arrays on the surface of indium phosphide wafers were introduced, the structure and experimental process of the electrochemical device were highlighted, and the resulting top and section views were also shown by animation. It can provide a useful reference guide for the large-scale fabrication of regular hole arrays on the surface of indium phosphide wafers.

This study examines how quantum confinement energy affects the electrical characteristics represented by the energy gap. and the activation energy of indium arsenide (InAs) and indium phosphide (Inp) was studied using a computer program (MATLAB) version (R2012a), which is based on the characteristic matrix theory and Bruce's model, we found that the energy gap increases with the quantum confinement energy at small nanoscales, as well as the activation energy due to the quantum confinement effect, but these electrical properties decrease with the quantum confinement energy at large nanoscales. [ABSTRACT FROM AUTHOR]

Surface passivation is a critical aspect of preventing surface oxidation and improving the emission properties of nanocrystal quantum dots (QDs). Recent studies have demonstrated the critical role of surface ligands in determining the performance of QD-based light-emitting diodes (QD-LEDs). Herein, the underlying mechanism by which the capping ligands of InP/ZnSe/ZnS QDs influence the brightness and lifetime of the QD-LEDs is investigated. The electrochemical results demonstrate that highly luminescent InP/ZnSe/ZnS QDs exhibit modulated charge injection depending on the length of the surface ligand chains: short alkyl chains on the ligands are favorable for charge transport to the QDs. In addition, the correlation between the spectroscopic and XRD analyses suggests that the length of the ligand chain tunes the ligand–ligand coupling strength, thereby controlling the inter-QD energy transfer dynamics. The present findings shed new light on the crucial role of surface ligands for InP/ZnSe/ZnS QD-LED applications. [ABSTRACT FROM AUTHOR]

The molar absorption coefficients of spherical InP, ZnS, and InP(core)/ZnS(shell) nanoparticles have been calculated from the complex permittivities of the corresponding bulk semiconductors. The results are valid in the short-wavelength region of the absorption spectrum, where the quantum size effect is insignificant. For the imaginary part of the polarizability of core/shell nanoparticles, a formula has been obtained that is convenient for calculations in real numbers. [ABSTRACT FROM AUTHOR]

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The thermal conductivity of Si-doped thin films of indium phosphide grown via metalorganic vapour-phase epitaxy at different carrier concentrations and thicknesses was measured from 80 to 450 K using time domain thermoreflectance. Additionally, phonon gas modeling was conducted to characterize the various scattering mechanisms that contribute to the thermal transport in these materials. A sensitivity analysis based on the phonon gas model showed that while thickness has a greater influence on the thermal conductivity than carrier concentration at the micron-scale for all samples, point defects due to Si-dopant atoms at carrier concentrations of ∼1019 cm−3, as well as the presence of extended defects that are most likely present due to dopant saturation, have a significant impact on thermal transport as a result of increased phonon scattering, decreasing the thermal conductivity by 40% or more. [ABSTRACT FROM AUTHOR]

Colloidal indium phosphide quantum dots (In(Zn)P/ZnS QDs) show potential for application in the field of light emitting diodes (LED) and Mini/Micro‐LEDs displays due to their tunable emission and low toxicity. However, the performance of blue‐emitting indium phosphide QDs is still lagging behind that of red and green. Herein, a facile method to overcome this difficulty is proposed. The highly active Zn(ClO4)2 precursor is injected into the reaction mixture during the nucleation process to enhance zinc incorporation, which generates the In(Zn)P alloy QDs with enlarged bandgap. At the same time, the increase of zinc content can inhibit excessive growth of In(Zn)P QDs, and significantly improve its size distribution. The monodisperse In(Zn)P/ZnS QDs exhibit excellent blue emission (466 nm) and have the narrowest full width at half maxima (41 nm) of blue emission In(Zn)P QDs ever reported. This work provides a feasible and effective strategy for obtaining narrow‐band blue‐emitting In(Zn)P/ZnS QDs. [ABSTRACT FROM AUTHOR]

III–V semiconductors are among the highest performing materials for solar energy conversion devices. Exposing III–V semiconductors to a hydrogen plasma can improve optoelectronic properties and is a critical step in fabricating efficient InP solar cells. However, there is a limited understanding of the changes induced by hydrogen plasma exposure to the surface and in the bulk of III–V semiconductors. Herein, it is demonstrated that a 19.3% efficient p‐InP solar cell with a TiO2 electron selective contact layer can be achieved by exposing the InP substrate to hydrogen plasma. Detailed investigations employing ultraviolet photoelectron spectroscopy and capacitance–voltage measurement unveil that the hydrogen plasma exposure on p‐InP leads to charge carrier polarity inversion in the near‐surface region (charge inversion layer) while simultaneously reducing the carrier concentration (charge‐depleted layer) in the bulk. The study provides important insights into the impact of hydrogen plasma exposures on InP which may lead to more efficient optoelectronic devices such as solar cells, photodetectors, light‐emitting diodes, and photoelectrochemical cells. [ABSTRACT FROM AUTHOR]

With tunable emission in the full visible region, the ecofriendly InP quantum dots (QDs) show unique application prospects in light-emitting devices. At present, InP QDs suffer from wide-bandwidth emission, especially for electroluminescence (EL), which hinders their applications in high-performance display devices. Here, we report a facile one-pot synthesis of narrow-bandwidth InP/ZnSeS/ZnS QDs using a safe phosphorus source of tris-(dimethylamino)-phosphine, in which the ZnSeS inner-shell layer is formed via temperature-gradient solution growth from 240 to 280 °C. The synthesized green QDs have a high photoluminescence quantum yield (PLQY) of 91% and full width at half-maximum (fwhm) of 36 nm. Moreover, the resultant quantum dot light-emitting devices (QLEDs) also show a narrow fwhm of 42 nm, which is the narrowest emission of green InP QLEDs based on a safe phosphorus source reported so far. Further modulation of the electron injection into the device by inserting a thin layer of lithium fluoride results in a peak external quantum efficiency of 5.56%. [ABSTRACT FROM AUTHOR]

We report phosphinidenes (PR) stabilized by an intramolecular frustrated Lewis pair (FLP) chelate. These adducts include the parent phosphinidene, PH, which is accessed via thermolysis of coordinated HPCO. The reported FLP‐PH species acts as a springboard to other phosphorus‐containing compounds, such as FLP‐adducts of diphosphorus (P2) and InP3. Our new adducts participate in thermal‐ or light‐induced phosphinidene elimination (of both PH and PR, R=organic group), transfer P2 units to an organic substrate, and yield the useful semiconductor InP at only 110 °C from solution. [ABSTRACT FROM AUTHOR]

Quantum dot light‐emitting diodes (QLEDs), regarded as promising candidates in the next‐generation display, have attracted much attention recently. In spite of the outstanding performance of cadmium‐based (Cd‐based) QLEDs, the toxicity of Cd hinders their wide application. Indium phosphide quantum dots (InP QDs) with heavy‐metal‐free feature and competitive performance are considered to be able to replace Cd‐based QDs as emitting layer in the QLEDs. Much progress is obtained in the red‐emitting and green‐emitting InP‐based QLEDs. However, the blue‐emitting ones are faced with great challenges and are demanded on full‐color display urgently, which is limited by the inferior performance of blue‐emitting InP QDs and lack of investigations about their QLED devices. In this review, the encountered challenges for high‐quality blue‐emitting InP QDs are presented. Common strategies for blue‐emitting InP QDs, including size engineering, composition engineering, and surface engineering are presented and analyzed. The progress of blue‐emitting InP‐based QLEDs, which strongly relies on the advances of materials, is also summarized. Finally, some perspectives from device physics are provided and discussed to inspire more efficient strategies toward blue‐emitting InP‐based QLEDs. [ABSTRACT FROM AUTHOR]

Development and scalable nanomanufacturing of high‐quality heavy metal‐free quantum dots (QDs) with high‐dimensional experimental design spaces still remain a challenge. In this work, a universal flow chemistry framework for accelerated fundamental and applied studies of heavy metal‐free QDs with multi‐stage chemistries is presented. By introducing flexible time‐ and temperature‐to‐distance transformation using modular fluidic blocks, an in‐flow synthetic route of InP QDs with the highest reported first excitonic absorption peak to valley ratio is unveiled with a reaction time one order of magnitude faster than batch reactors. The flexible time‐ and temperature‐to‐distance transformation as an enabling factor for generalization of flow reactors toward the accelerated discovery, development, and nanomanufacturing of high‐quality emerging nanomaterials for next‐generation energy, display, and chemical technologies is discussed. [ABSTRACT FROM AUTHOR]

The results of studies on the optical properties of colloidal InP/ZnS nanocrystals stabilized by a heterobifunctional polymer based on polyvinylpyrrolidone are presented. The optical absorption and photoluminescence spectra of (i) solutions containing different concentrations of nanocrystals and (ii) film samples, as well as the temperature dependences of these spectra in the range of 6.5–296 K are analyzed. An inhomogeneous broadening of the exciton optical bands was observed, which is associated with a broad size distribution of nanocrystals. It was established that the temperature-induced shift of the exciton absorption and emission maxima is mainly due to the interaction with acoustic phonons. It was shown that quenching of defect-related luminescence involves the local energy levels of the dangling bonds of phosphorus atoms at the core—shell interface, while the temperature stability of exciton emission is governed by the thickness of the ZnS shell. [ABSTRACT FROM AUTHOR]

Semiconductor-based laser particles (LPs) with an exceptionally narrowband spectral emission have been used in biological systems for cell tagging purposes. The fabrication of these LPs typically requires highly specialized lithography and etching equipment and is typically done in a cleanroom environment, hindering the broad adoption of this exciting new technology. Here, using only easily accessible laboratory equipment, we demonstrate a simple layer-by-layer fabrication strategy that overcomes this obstacle. We start from an indium phosphide substrate with multiple epitaxial indium gallium arsenide phosphide layers that are sequentially processed to yield LPs of various compositions and spectral properties. The LPs isolated from each layer are characterized, exhibiting excellent optical properties with a lasing emission full width at half maximum as narrow as <0.3 nm and typical thresholds of ∼6 pJ upon excitation using a 3 ns pulse duration 1064 nm pump laser. The high quality of these particles renders them suitable for large-scale biological experiments, including those requiring spectral multiplexing. [ABSTRACT FROM AUTHOR]