Search

Novel back-illuminated modified uni-traveling- carrier photodiodes (MUTC-PDs) are reported to demonstrate wide bandwidth and high output power performance at D-band (110–170 GHz) regime. A comprehensive design model is employed to predict and tune the frequency response by incorporating coplanar waveguides (CPWs) with different inductive peaking effects. As a demonstration, 4.5-μm-diameter photodiodes with two types of CPWs are fabricated to exhibit different frequency response profiles. Both PDs exhibit a 3-dB bandwidth over 150 GHz and the measured frequency responses are in excellent agreement with simulations. Thanks to the proper design of the CPW electrodes, the two PDs exhibit an output power roll-off of only 4.3 dB and 4.8 dB from dc to 170 GHz, respectively, and high saturation performance is maintained over the broadband frequency range of 130–170 GHz.

An indium phosphide photonic integrated circuit (PIC) was demonstrated for integrated path differential absorption lidar of atmospheric carbon dioxide (CO2). The PIC consists of two widely tunable sampled grating distributed Bragg reflector (SGDBR) lasers, directional couplers, a phase modulator, a photodiode, and semiconductor optical amplifiers (SOAs). One SGDBR laser, the leader, is locked to the center of an absorption line at 1572.335 nm using the on-chip phase modulator and a bench-top CO2 Herriott reference cell. The other SGDBR laser, the follower, is stepped in frequency over ±15 GHz around 1572.335 nm to scan the target CO2 absorption line. The follower laser is offset locked to the leader laser with an optical phase lock loop. An SOA after the follower laser generates a pulse at each frequency step to create a train of pulses that samples the target CO2 absorption line. The PIC components and subsystem are characterized and evaluated based on target performance requirements. The leader laser demonstrated a 236-fold improvement in frequency stability standard deviation when locked compared to free running and the follower laser frequency stability standard deviation compared to the leader laser was 37.6 KHz at a 2 GHz programmed offset.

Indium phosphide (InP) nanocrystals are emerging as an alternative to heavy metal containing nanocrystals for optoelectronic applications but lag behind in terms of synthetic control. Herein, luminescent wurtzite InP nanocrystals with narrow size distribution were synthesized via a cation exchange reaction from hexagonal Cu3P nanocrystals. A comprehensive surface treatment with NOBF4 was performed, which removes excess copper while generating stoichiometric In/P nanocrystals with fluoride surface passivation. The attained InP nanocrystals manifest a highly resolved absorption spectrum with a narrow emission line of 80 meV, and photoluminescence quantum yield of up to 40%. Optical anisotropy measurements on ensemble and single particle bases show the occurrence of polarized transitions directly mirroring the anisotropic wurtzite lattice, as also manifested from modeling of the quantum confined electronic levels. This shows a green synthesis path for achieving wurtzite InP nanocrystals with desired optoelectronic properties including color purity and light polarization with potential for diverse optoelectronic applications.

A terahertz (THz) fundamental oscillator IC with high efficiency and compact chip size based on an indium phosphide (InP)-based resonant tunneling diode (RTD) is proposed. The oscillator is designed by utilizing a low-frequency bias stabilizer, along with utilizing a negative differential resistance oscillator topology. The oscillator is fabricated by using an InP monolithic THz integrated circuit multilayer process. The fabricated oscillator shows a high dc-to-RF power efficiency ( η ) of 0.274 % with a low dc power consumption of 3.4 mW and an RF output power of 9.3 μ W at an oscillation frequency of 692 GHz. The IC exhibits a chip size of 300 × 380 μ m2 excluding the measurement pads. The achieved η and chip size are good values among THz oscillators above 500 GHz reported to date.

The use of nanostructures over traditional bulk and thin-film solar cells (SCs) increases the efficiency per unit volume due to the coupled effects of intrinsic antireflection and strong excitation of resonance modes. The structural optimization of InP nanowires (NWs) provides a deep insight into the electrical and optical parameters of NWs influenced by structural morphology. Here, we propose a core–shell structure using n-InP NW as a core coated with PEDOT:PSS/MoO3 shell. We simulated the resultant structure using the finite difference time domain (FDTD) and device modules of Lumerical to investigate its optical and electrical behavior. The optical simulation predicts that a hole-selective layer over InP core increases the absorption of incident photons. An optimized thickness of shell reduces the required core material without affecting the ideal current density, resulting in low manufacturing cost. For core doping of $5\times10$ 18 cm−3, surface recombination velocity (SRV) of 104 cm/s, and minority carrier lifetime ( $\tau_{p}$ ) of 40 ns, an efficiency of ~25% can be achieved. In this article, we have also compared the optical and electrical characteristics of uncoated, PEDOT:PSS/InP NW and ITO/InP NW and electron-selective oxide-coated InP NW with our proposed structure and found that our proposed structure PEDOT:PSS/p-MoO3/ n-InP heterojunction NWSC exhibits better photovoltaic (PV) performance than the above-mentioned structures.

High-speed and robust optical beam-steering device will be the key component for various applications, such as LiDAR (light detection and ranging) and free-space optical communication. Optical phased arrays (OPAs) integrated on semiconductor chips have recently received increasing attention due to the high-speed operation, compactness, and low cost. In particular, indium phosphide (InP)-based OPAs are advantageous for high-output-power applications at 1.55- $\mu \text{m}$ eye-safe wavelength, owing to their capability of monolithically integrating active components, such as high-power lasers and optical amplifiers. In this letter, we design and fabricate, to the best of our knowledge, the largest-scale InP-based OPA and experimentally demonstrate its beam-steering operations. The fabricated OPA consists of 100 waveguides with carrier-injection-based phase shifters, densely integrated on 7 mm $\times5$ mm footprint. A focused beam width of 0.11° is steered across the free spectral range of 8.88°, corresponding to more than 80 resolvable points. This is the largest number of resolvable points obtained by a monolithic InP OPA. The response time of the OPA is confirmed to be less than 16 ns, which is limited by the driver circuit. This work paves the way for realizing compact beam-steering modules for high-speed and high-output-power imaging applications.

Avalanche photodiodes (APDs) are used in optical receivers of high-speed optical communication systems to improve signal-to-noise ratio over conventional photodiodes. Low excess noise characteristics are crucial for APDs to preserve the benefits associated with high internal gains. In this work, we presented room temperature data of avalanche gain and excess noise factors of Al0.85Ga0.15As0.56Sb0.44 APDs using pure and mixed carrier injection profiles. Using pure electron injection, the best possible excess noise performance for a given avalanche width was measured with an excess noise factor https://doi.org/10.15131/shef.data.15082455 )

In this letter, we present a 25-GSa/s wideband track-and-hold amplifier using 0.8- ${\mu }\text{m}$ indium phosphide (InP) process for high-speed analog sampling front-end. In this design, an active peaking input buffer is first used in the base–collector switching diode sampler. Moreover, it is carefully calculated and analyzed. The dominant pole in the signal path of the circuit is canceled by one zero produced by the active peaking structure; therefore, the bandwidth (BW) is extended. The experimental results show that a total harmonic distortion (THD) of less than −27 dBc and a spurious-free dynamic range (SFDR) of better than 32.5 dB are demonstrated at a 25-GSa/s sampling rate. In the hold mode, the isolation is better than −42 dB. In addition, it has an 0.156 ${f_{T}}$ BW from dc to 25 GHz within 160-GHz ${f_{T}}$ , which is a very competitive value compared with other reported track-and-hold amplifiers (THAs) using the InP process.

We fabricate a membrane InP-based electro-absorption modulator (EAM), in which an InGaAsP-based multiple-quantum-well (MQW) absorption region is buried with an InP layer, on Si-waveguide circuits. By optical coupling between the MQW absorption region and Si core, a low-loss and large-absorption-length (300-μm-long) supermode waveguide is designed to suppress electric-field screening at high optical input power. The EAM is fabricated by combining direct bonding of the MQW layer and regrowth of the InP layer on a thin InP template bonded on a silicon-on-insulator wafer. The fabricated membrane EAM shows an on-chip loss of less than 4 dB at wavelengths over 1590 nm and temperatures from 25 to 50 °C. Since the membrane lateral p-i-n diode structure is beneficial for reducing the RC time constant of a lumped-electrode InP-based EAM, the EO bandwidth of the EAM is around 50 GHz without a 50-ohm termination up to fiber-input power of 10 dBm. Using the device, we demonstrate clear eye openings for 56-Gbit/s NRZ and 112-Gbit/s PAM4 signals at temperatures from 25 to 50 °C.

We investigated theoretically a waveguided EAM (Electro-Absorption Modulator) based on ISBT (Intersubband Transitions) in an In(0.53)Ga(0.47)As/AlAs/AlAs(0.56) Sb(0.44) A-CDQWs (Asymmetric Coupled Double Quantum Wells) lattice-matched to InP at telecommunication wavelength ( $\lambda =1.55~\mu \text{m}$ ) which offers ultrahigh-speed and moderate voltage swing. Likewise, the temperature dependency in the In(0.53)Ga(0.47)As/AlAs/AlAs(0.56) Sb(0.44) A-CDQWs was investigated at different temperatures from 300 K to 400 K and evidently the InP-based ISB (Intersubband) modulator offers better temperature stability (~ 0.05 nm/C) compared to the InP-based IB (Interband) modulator. The EAM investigated here is anticipated to have a RC-limited speed ( $f_{3d\,B}$ ) of ~300 GHz with insertion loss of 5.1 dB, 10 dB extinction ratio and 5.18 dB/V modulation efficiency at a peak-to-peak voltage of 2.0 V which can support a data rate of up to 600 Gbps and beyond.

A photoreceiver consisting of indium phosphide (InP) balanced photodiodes (PD) on Si $_3$ N $_4$ waveguides and a transimpedance amplifier (TIA) fabricated in a silicon germanium (SiGe) BiCMOS process is demonstrated. The InP PDs, heterogeneously integrated on a silicon substrate, achieve external (internal) responsivities of 0.75 (0.9) A/W, bandwidths of 4 GHz, and common mode rejection ratios (CMRR) of greater than 40 dB when illuminated differentially. The TIA achieves 74 dB $\bf \Omega$ of transimpedance gain with a 1 dB peak, a bandwidth of 3 GHz, and a low equivalent input noise current density of 7.2 pA/ $\sqrt{Hz}$ when loaded with a C $_{PD}$ of 380 fF. The full photoreceiver achieves high conversion gain of more than 2 kV/W up through 2 GHz, and a low NEP of 8 pW/ $\sqrt{Hz}$ up through 1.6 GHz. The photoreceiver optical CMRR is measured to be 36 dB.

The strong chemical-stimulating and modifying effect of BiРxV1 – xO4 on the process of InP thermal oxidation, which consists in blocking the diffusion of non-oxidized In into the forming films and the intense formation of a vanadate-phosphate skeleton, is established. The presence of V2O5 in the synthesized films, which has catalytic activity in the processes under study, with an effective activation energy of about 50 kJ/mol and a large relative increase in the thickness throughout the entire process, suggests a catalytic component of the oxidation mechanism. The formation of the phosphate skeleton of the films during the oxidation of YVO4/InP occurs due to secondary interactions of the oxidized components of the semiconductor similar to the mechanism of the intrinsic oxidation of indium phosphide.

This letter describes the design and measured performance of an $E$ -/ $W$ -band GaN MMIC low-noise amplifier based on a 90-nm T-gate GaN technology. The GaN technology is characterized by a peak fT of 145 GHz and an NFmin of ~1.2 dB at 50 GHz. The LNA is comprised of a four-stage common-source amplifier designed to operate over a 70–110-GHz frequency band. From 70 to 89 GHz, the amplifier achieves 15–17.9 dB of gain and an NF of 3.5–4.2 dB over a 75–83 GHz measured subband. From 90 to 110 GHz, the amplifier achieves a gain from 15.8 to 19.2 dB and an NF of 3.3–3.8 dB over a 91–96-GHz measured subband. These are believed to be the lowest NFs achieved from a single GaN amplifier covering both $E$ - and $W$ -frequency bands. The MMIC is $2.4\times1.3$ mm2 in size and consumes 200 mW of dc power from a 5-V supply. The GaN LNA can be integrated with a PA and RF switch to form a compact GaN TR MMIC solution.

Purpose: The article proposes a methodology for determining the chemical quality criterion of porous layers synthesized on the surface of semiconductors, based on taking into account the chemical parameters of the surface that can affect the properties of nanostructures. Design/methodology/approach: The chemical quality criterion was evaluated in terms of stoichiometry, stability of structures over time, uniformity of distribution over the surface, and the presence of an oxide phase. As an example, a calculation is demonstrated for the por-InP/InP structure synthesized on a mono-InP surface. The results of calculating the chemical quality criterion were evaluated using the Harrington scale to rank samples by quality level. Findings: A chemical criterion for the quality of porous layers synthesized on the surface of semiconductors has been developed. This criterion contains a set of indicators sufficient for a comprehensive assessment of the surface condition and is universal in nature. The studies carried out make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors and open up new perspectives in the construction of a model of self-organization of a porous structure. Research limitations/implications: The chemical quality criterion does not allow evaluating the obtained nanostructures in terms of geometric parameters. Therefore, in the future, there is a need to develop a morphological quality criterion and determine a methodology for assessing a generalized quality criterion for nanostructures synthesized on the surface of semiconductors, which may include economic, environmental, technological indicators, and the like. Practical implications: Study results are expedient from a practical point of view, since they make it possible to reasonably approach the determination of the modes of electrochemical processing of semiconductors, synthesize nanostructures with predetermined properties, and create standard samples of nanomaterial composition.Originality/value: Methodology for assessing the quality of porous semiconductors by a chemical criterion has been applied for the first time in engineering science. The article will be useful to engineers, who are engaged in the synthesis of nanostructures, researchers and scientists, as well as specialists in nanometrology.

High resolution and wide color gamut are two key requirements for novel display technologies. Owing to the distinguishing advantages over conventional displays, such as intrinsic wide color gamut and the possibility to achieve high resolution, quantum dot light-emitting diodes (QLED) have drawn considerable attention in recent years. On the other hand, indium phosphide quantum dots (InP QDs) have shown a great potential as a replacement for cadmium selenide (CdSe) QDs in display applications due to the inherent toxicity of cadmium-based QDs. In this study, we investigate a top-emission InP-based green QLED with optimized angular distribution. By adjusting the electrical and optical architecture, the device exhibits improved properties with a maximum current efficiency of 30.1 cd/A and a narrowed full width at half maxima (FWHM)of 31 nm, which are the best results ever reported to our knowledge.

This work presents a high efficiency, compact 80–110-GHz InP power amplifier (PA) based on stacked common base (CB) topology and a counterpart design using conventional stacked common emitter (CE) topology. The comparison between the two exhibits that the former delivers higher power gain, superior-gain compression behavior (linearity), and higher back-off efficiency in $W$ -band in 250-nm InP heterojunction bipolar transistor (HBT). At 90 GHz, the stacked CB/CE PA achieves 11.8 dB/6dB gain, 33%/34% peak PAE, 16.8%/14.5% PAE at 6-dB back-off, and Psat of 18.7 dBm/19.6 dBm. Modulation test exhibits an EVM of 2.38% at 11.8-dBm average power supporting 3 Gbps 64-QAM for the stacked CB PA. The stacked CB PA with 17.9–18.9-dBm Psat across 80–110 GHz demonstrates one of the highest efficiency, broadband and linear PAs in $W$ -band using InP technology.

The effect of atomic-layer-deposition (ALD)-derived Al2O3 passivation layer on the interface quality of Er2O3/Al2O3/InP laminated stacks and the improvement of electrical performance has been investigated systematically. The chemical bonding states measured by high-resolution X-ray photoelectron spectroscopy (XPS) reveal that the ALD-derived Al2O3 passivation layer can effectively inhibit the diffusion of substrate elements to optimize the interface quality. Electrical characterizations show that the optimized sample has demonstrated improved electrical properties, including the large dielectric constant of 20 and the suppressed leakage current density of $4.10\times 10^{-7}$ cm2. In addition, the leakage current conduction mechanisms are also investigated as a function of thickness of Al2O3 passivation layer. The optimized interface state density extracted from the conductance method has reduced from $1.30 \times 10^{12}$ eV−1cm2 of Er2O3/InP to $7.27 \times 10^{11}$ eV−1cm2 of Er2O3/Al2O3/InP by adjusting the passivation layer thickness. As a result, it can be also confirmed that the passivation treatment is beneficial to inhibit the element’s diffusion and optimize the interface quality, significantly controlling the capacitor degradation caused by the leakage current through the stacked oxide layer.

In this letter, we present a novel analysis and design approach of self-oscillation frequency (SOF) for 0.8- ${{\mu }}\text{m}$ indium phosphide (InP) double-heterojunction bipolar transistor (DHBT) emitter-coupled logic (ECL) and current-mode logic (CML) static frequency dividers. SOF of ECL and CML dividers is designed to be the maximum value after theoretical analysis and multiparameter optimization. The results show that the SOF of the ECL and CML divider is 62 and 37.5 GHz, respectively. With sinusoidal waveform input, the operating frequency range of the ECL divider is from 0.1 to 65 GHz, and CML is from 0.1 to 55 GHz, while the cut-off frequency ${f_{T}}$ is 150 GHz. For ECL, the ${f_{T}}$ utilization of SOF (SOF ${/}{f_{T}}$ ) is 0.413, and CML is 0.25. These are the maximum SOF results that can be designed for the two dividers under the same design conditions.

Water is considered a pivotal molecule for colloidal III–V indium phosphide (InP) quantum dots (QDs) and significantly affects the QD crystal growth and photoluminescence (PL) stability. Herein, we...

We report uniform Type-II GaInAsSb/InP UTC-PDs, and compare their performance to devices fabricated with GaAsSb uniform and graded (composition and doping) absorbers of the same thickness. The quaternary UTC-PDs show a transit limited bandwidth of 274 GHz in contrast to 107 and 185 GHz for uniform and graded GaAsSb absorber UTC-PDs. Because the uniform quaternary and ternary UTC-PDs only differ in their absorber material, the findings conclusively demonstrate enhanced transport in GaInAsSb. Performance comparison to GaInAs-based devices from the literature suggest that GaInAsSb is a superior absorber material for λ = 1.55 μm high-speed photodetectors. Additionally, the external responsivity of the GaInAsSb UTC-PDs (0.094 A/W) is ~34% higher than the GaAsSb PDs (0.070 A/W). This is the first demonstration of a quaternary GaInAsSb absorber in UTC-PDs., Journal of Lightwave Technology, 39 (7), ISSN:0733-8724, ISSN:1558-2213

Single photon avalanche diodes (SPADs) are key enabling technologies for a wide range of applications in the near-infrared wavelength range. Recently, AlAs0.56 Sb0.44 (hereafter AlAsSb) lattice-matched to InP has been demonstrated for extremely low excess noise avalanche photodiodes (APDs) due to its large disparity between electron and hole ionization coefficients ( $\alpha $ and $\beta $ respectively). The $\alpha /\beta $ ratio also plays a role in Geiger mode operation as it affects the avalanche breakdown probability and hence detection efficiency. In this work, we theoretically investigate the performance of AlAsSb based SPADs. The probability of breakdown for electron-initiated Geiger mode operation increases more sharply with multiplication region width due to progressively more dissimilar ionization coefficients. In comparison with other common avalanche materials, such as InAlAs, InP and Si, our result also suggests that SPADs based on AlAsSb have a sharper breakdown probability than the other three materials under similar low overbias ratio. The calculated breakdown probability of 0.81 in AlAsSb is 0.18 and 0.28 higher than that of InAlAs/Si and InP respectively at 5% overbias ratio and with avalanche region width of 1500 nm.

Using quantum dot (QD) structures as active material for optoelectronics was already in focus before the development of quantum well (QW) lasers and before semiconductor lasers occupied an important place in the market. The big step in reducing laser threshold conditions by substituting bulk gain materials with QWs should find a logical continuation by further reducing the dimensionality toward full 3D carrier confinement by QDs. This was predicted by theoretical considerations at the beginning of the 1980s [1], [2]. However, no practical technologies were available at that time. Top-down approaches, as originally addressed, to produce nanoscale species on very large surfaces and interface areas resulted in the accumulation of a large defect density within the active region and the domination of nonradiative carrier recombination mechanisms. Only during the early 1990s was a major breakthrough achieved with the introduction of the bottom-up approach of strain-driven, self-organized epitaxial QD growth. The first lasers were obtained in the gallium arsenide (GaAs)-based material system [3].

This report of the reddest emitting indium phosphide quantum dots (InP QDs) to date demonstrates tunable, near-infrared (NIR) photoluminescence (PL) as well as PL multiplexing in the first optical tissue window while avoiding toxic constituents. This synthesis overcomes the InP "growth bottleneck" and extends the emission peak of InP QDs deeper into the first optical tissue window using an inverted QD heterostructure, specifically ZnSe/InP/ZnS core/shell/shell nanoparticles. The QDs exhibit InP shell thickness-dependent tunable emission with peaks ranging from 515-845 nm. The high absorptivity of InP yields effective photoexcitation of the QDs with UV, visible, and NIR wavelengths. These nanoparticles extend the range of tunable direct-bandgap emission from InP-based nanostructures, effectively overcoming a synthetic barrier that has prevented InP-based QDs from reaching their full potential as NIR imaging agents. Multiplexed lymph node imaging in a mouse model demonstrates the potential of the NIR-emitting InP particles for in vivo imaging.

A mono-bit digital receiver circuit for instantaneous frequency measurement is presented. The circuit is co-designed with Indium Phosphide Double Heterojunction Bipolar Transistor and complementary metal oxide semiconductor (CMOS) devices. The chip is fabricated by InP/CMOS three-dimensional (3D) heterogeneous integration using the wafer-level bonding technique. The measurable signal frequency within + 15 to − 25 dBm power is up to 7.5 GHz with a 14-GHz clock. Compared to an integrated circuit (IC) with a traditional InP or CMOS technologies, the proposed chip could benefit from both InP and CMOS technology. In the heterogeneous integration, InP devices provide high operating frequency, broad signal bandwidth, and large input signal dynamic range, while CMOS devices achieve complex function with low power consumption. In this way, the system FoM is improved for a mono-bit digital receiver while the system power consumption is kept the same. This work also shows the great potential of the 3D heterogeneous integration for the high-performance mixed-signal and multifunction radio-frequency ICs.

Epitaxially integrating III-V lasers with Si-photonics is the key for compact, efficient, and scalable photonic integrated circuits (PICs). Here we present an investigation of a path forward in integrating III-V functionalities on industry-standard silicon-on-insulator (SOI) platforms using selective area hetero-epitaxy. Based on our recently developed methods of selectively growing device quality InP on (001)-oriented SOI wafers, we demonstrated InP stripes and segments, with dimensions varying from a few hundred nanometers to a few micrometers. The flexible epitaxy of InP on SOI together with the unique “bufferless” trait will enable efficient light interfacing with Si-based photonic devices using either evanescent or butt coupling schemes. We simulated the possibility of employing the micrometer-scale InP on insulator to realize electrically driven lasers and found that the metal induced optical loss is negligible when the InP dimension exceeds 4.0 μm. The potential of utilizing this selective area growth method to realize fully integrated Si-photonics is illustrated.

In this work we report the results of high density multi-channel optical multiprobes with pitches of 25 ${\mu }\rm{m}$ and 50 ${\mu }\rm{m}$ that provide edge-coupling used for on-wafer parallel testing of photonic integrated circuits. The probes are fabricated in an oxynitride platform and test demonstrations were carried out of edge-coupled indium-phosphide based photonic integrated circuits (PICs). Thirty-two optical parallel connections are simultaneously, passively aligned between the probe and the PIC by means of integrated guiding channels. The initial placement tolerance is more than 4 ${\mu }\rm{m}$ to give a passive alignment with an optical power variation of less than 1 dB. Multi-port loop-back optical power measurements are reported and the wavelength-dependent net modal gain of integrated semiconductor optical amplifiers was measured to further validate the concept.

We present a characterization method for polarization converters which improves the accuracy of traditional characterization methods significantly. An experimental demonstration of the method is presented on the InP-membrane-on-silicon (IMOS) platform. The design and fabrication of the polarization converter is discussed, as well as the simulated polarization conversion efficiency. A device of only 4 microns is shown to achieve 97.5%±0.5% polarization conversion, corresponding to an extinction ratio of -16± 0.9 dB. The traditional characterization method is compared to the new 4-port method, and the accuracy is improved from up to 20% to 0.5%.

In this study, green indium phosphide (InP) quantum dots (QDs) were synthesized using a tris(dimethylamino)phosphine ((DMA)3P) phosphorus source and applied to electroluminescent quantum light-emitting diodes (QLEDs). The (DMA)3P precursor is safer and more cost-effective than the conventional tris(trimethylsilyl)phosphine. The emission peak of the InP QDs was shifted to the green region from the red by replacing the conventional zinc precursor ZnCl2 with ZnI2. The surface reaction rate was limited using ZnI2 in the core formation step, yielding small-sized QDs to achieve green emission. In addition, with the optimal ZnSeS intermediate shell and outer shell, the maximum quantum yield of 67.5% with a narrow full width at half maximum of 46 nm was achieved for the (DMA)3P-based green-emitting InP@ZnSeS/ZnS QDs. QLEDs were demonstrated with the (DMA)3P-based green InP QDs, and their efficiency was maximized by optimizing the Mg doping ratios in the electron transport layer (ETL) of ZnMgO. The maximum external quantum efficiency of 1.68% and current efficiency of 4.79 cd/A were achieved with an optimal doping ratio of 12.5% ZnMgO for the (DMA)3P-based green InP QLEDs. This study demonstrates that safer (DMA)3P phosphide source-based green InP QDs are effective in achieving low-cost InP QLEDs.

The investigation on the effect of illumination power intensities for a thermophotovoltaic (TPV) system is crucial to enhance the TPV cell performance. To date, the studies on the effect of illumination intensities were limited to solar photovoltaic cells application. Meanwhile, the reported work on the impact of infrared illumination intensities on TPV cells are done at limited temperatures and intensities. The effects of TPV intensities on all performance parameters are not comprehensively studied and fully elucidated. Therefore, this paper investigates the performance of indirect-bandgap Germanium (Ge) and direct-bandgap Indium Gallium Arsenide (InGaAs) cells under various TPV spectral irradiances. Silvaco TCAD simulation software was used to investigate the effect of blackbody temperatures ranging from 800 to 2000 K with different illumination intensities on the TPV cell performances. It was found that higher conversion efficiencies are achieved for both TPV cells under higher illumination intensities due to the increase in open-circuit voltage and fill factor. As the beam intensity increases for temperatures >1600 K, fill factor slowly increases for the Ge cell, but decreases for the InGaAs cell due to the increase in the I2Rs losses associated with the high current. The finding demonstrates that the open-circuit voltage of indirect-bandgap TPV cell is significantly increased with higher illumination intensities. The variations in cells performance are explicitly explained based on factors such as TPV design structure and the physical properties of semiconductor at varying illumination intensities. The performance of both TPV cells were also analyzed at the minimum optical losses. Average efficiencies of Ge and InGaAs TPV cells were increased to 26.05% and 27.92%, respectively, when the optical losses were minimized with anti-reflection coating and thicker absorber layer. The results of this work demonstrate that by detailed consideration of the effect of spectral irradiances, a high-performance TPV system can be developed.

Colloidal semiconductor nanocrystals with tunable optical and electronic properties are opening up exciting opportunities for high-performance optoelectronics, photovoltaics, and bioimaging applications. Identifying the optimal synthesis conditions and screening of synthesis recipes in search of efficient synthesis pathways to obtain nanocrystals with desired optoelectronic properties, however, remains one of the major bottlenecks for accelerated discovery of colloidal nanocrystals. Conventional strategies, often guided by limited understanding of the underlying mechanisms remain expensive in both time and resources, thus significantly impeding the overall discovery process. In response, an autonomous experimentation platform is presented as a viable approach for accelerated synthesis screening and optimization of colloidal nanocrystals. Using a machine-learning-based predictive synthesis approach, integrated with automated flow reactor and inline spectroscopy, indium phosphide nanocrystals are autonomously synthesized. Their polydispersity for different target absorption wavelengths across the visible spectrum is simultaneously optimized during the autonomous experimentation, while utilizing minimal self-driven experiments (less than 50 experiments within 2 days). Starting with no-prior-knowledge of the synthesis, an ensemble neural network is trained through autonomous experiments to accurately predict the reaction outcome across the entire synthesis parameter space. The predicted parameter space map also provides new nucleation-growth kinetic insights to achieve high monodispersity in size of colloidal nanocrystals.

Indium phosphide core/shell nanocrystals hold promise to replace heavy-metal-based emissive materials for bioimaging and optoelectronic applications. Uniformity of the shell passivation and the int...

This article reports a detailed approach toward optimization of on-wafer thru-reflect-line (TRL) calibration structures for submillimeter-wave characterization of a state-of-the-art indium-phosphide (InP) technology, validated by thorough experimentation and electromagnetic (EM) simulation. The limitations of the existing RF test structures for high-frequency measurements beyond 110 GHz are analyzed through EM simulation. Using an optimization procedure based on calibration of raw EM simulated data, on-wafer TRL calibration structures were developed and fabricated in a subsequent run of this technology. Measurements could be achieved up to 500 GHz on the passive devices and up to 330 GHz on the InP double heterojunction bipolar transistors (DHBTs). The transistor measurements were validated by comparison with the HiCuM compact model simulation to 330 GHz for the InP DHBTs.

Here, we report efficient and stable indium phosphide (InP) based inverted red quantum dot light-emitting diodes (QLEDs) using a new high mobility and deep HOMO level hole transport layer (HTL) and...

Most recently, III–V based ultrathin solar cells have attracted considerable attention for their inherent advantages, such as increased tolerance to defect recombination, efficient charge carrier separation, photon recycling, flexibility, and reduced material consumption. However, so far, almost all reported devices make use of conventional doped p-i-n kind of structures with a wide-bandgap III–V lattice-matched epitaxial window layer, for passivation and reduced contact recombination. Here, we show that a high-efficiency device can be obtained utilizing an InP thin film of thickness as low as 280 nm, without the requirement of a conventional p-n homojunction or epitaxial window layer. This is achieved by utilizing a wide-bandgap electron and hole selective contacts for electrons and holes transport, respectively. Under ideal conditions [assuming interface recombination velocity (IRV) = 103 cm/s and bulk lifetime = 1 μs], the proposed solar cell structure can achieve efficiency as high as 28%. Although, in the presence of bulk and interface Shockley–Read–Hall recombination, the efficiency reduces, still for bulk minority carrier lifetime as low as 2 ns and an IRV as high as 105 cm/s, an efficiency of ∼22% can be achieved with InP thickness as low as 280 nm. The proposed device structure will be beneficial in cases where the growth of controlled p-n homojunction and window layer can be tedious as in case of low-cost deposition techniques, such as thin-film vapour–liquid–solid and close-spaced vapour transport.

This article describes the design and performance of a 140-GHz SiGe and a 100-GHz InP triple-stacked HBT distributed amplifier with active bias terminations. The active bias network is configured to extend the practical low-frequency operation while maintaining gain flatness and linearity. Triple-stacked HBTs are used to increase the gain–bandwidth and linear output capability. The SiGe design is based on HBTs with a peak $f_{\mathrm {T}}/f_{\mathrm {max}}$ of 300/350 GHz and achieves 11.7 dB of gain and a bandwidth from baseband to 140 GHz. The InP HBT design is based on DHBTs with a peak $f_{\mathrm {T}}/f_{\mathrm {max}}$ of 250/250 GHz and obtains a gain of 10.8 dB and a bandwidth of 100 GHz. Although the SiGe design achieves 1.5 times higher gain–bandwidth, the InP DHBT design achieves ~3–4.5 dB greater IP3, $P_{\mathrm {1~dB}}$ , and $P_{\mathrm {3 ~dB}}$ while consuming only ~23% higher dc power. These results represent the first broadband performance comparison of near-identical (apples–apples) DA designs implemented in SiGe and InP HBT device technologies. Although there are previous reports of larger bandwidth distributed amplifiers in both InP and SiGe technologies demonstrated up through 200 GHz, the InP and SiGe monolithic microwave integrated circuits (MMICs) described in this article are believed to represent the highest bandwidths reported for HBT DAs using practical on-chip active bias terminations.

The gamma irradiation effect in indium phosphide (InP) heterojunction bipolar transistors (HBTs) is studied in this paper. The direct-current (DC) and alternating-current (AC) characteristics are i...

The use of epitaxial regrowth of InP on lattice-matched In0.53Ga0.47 As for passivation of photodiodes lateral mesa surfaces is investigated. The effect of the regrown layer was examined by photoluminescence and dark current measurements and compared with results obtained with SiO2 and Al2O3 passivation layers. The integrated intensity of steady-state photoluminescence of InGaAs covered by InP increased by a factor between 15.5 and 58.9, depending on the excitation wavelength, denoting a strong reduction of nonradiative recombination. This reduction is expected to be the result of a strong reduction of intragap surface states. For the same photoluminescence measurements, both SiO2 and Al2O3 oxide passivation instead showed a reduction of the photoluminescence intensity. The dark currents of p-i-n photodiodes showed less striking results, a fact that we claim, probably is related to residual doping of the InP regrown layer.

Among the III-V semiconductor materials, indium arsenide (InAs) nanowire (NWs) with high carrier mobility are expected to be alternative channels for high-performance and low-power field-effect transistors (FETs). However, there is a challenge in enhancing the on-state current for the InAs NW-channel vertical gate-all-around (VGAA) structures on Si. We investigated vertical InAs/InP core-shell (CS) NW-channels to enhance the current and demonstrated InAs/InP CS NW VGAA FETs. The InAs/InP CS NW-channel enhanced the on-state current while maintaining a small off-leakage current. The devices showed an on-state current of 40 $\mu \text{A}/\mu \text{m}$ , off-leakage current of 1 pA/ $\mu \text{m}$ , and subthreshold slope of 111 mV/dec at $\text{V}_{\text {DS}} =0.50$ V. The origin of the current enhancement suggests that there is a formation of two-dimensional electron gas (2DEG) in the InAs/InP CS NW-channel, and the characteristics of the InAs/InP CS NW VGAA FET revealed that the InP interlayer at draian edge and low source resistivity are important parameters to take advantage of 2DEG for CS NW VGAA FET.

We present a novel photonic integrated circuit (PIC) that monolithically integrates a racetrack colliding-pulse mode-locked laser with a pulse-picking electro-absorption modulator and a semiconductor optical amplifier on Indium Phosphide. We present detailed characterization of this PIC that includes optical pulse characterization, phase noise and long term stability under passive and hybrid mode-locking conditions. Allan deviation measurements made on the optical pulse train from the PIC show a fractional frequency instability of $8\times 10 ^{-11}$ at 1 second and follow a 1/ $\tau $ trend. We also demonstrate repetition rate reduction from ~10 GHz to ~500 MHz with an extinction ratio of ~14.65 dB using an on-chip pulse-picking electro-absorption modulator.

In this article, for the first time, a hybrid plasmonic (HP) ring resonator uni-traveling carrier pin-photodetector was numerically presented that offers a high responsivity of 0.68 A/W, a high bandwidth of over 125 GHz, and low footprint. This device has the capability of monolithic integration with HP-passive devices on the InP platform at an optical communication wavelength of 1550 nm.

InP is currently being used in various (opto)electronic and energy device applications. However, the high cost of InP substrates and associated epitaxial growth techniques has been huge impediments for its widespread use. Here, large-area monocrystalline InP thin films are demonstrated via a convenient cracking method, and the InP thin films show material properties identical to their bulk counterparts. Furthermore, the same substrate can be reused for the production of additional InP thin films. This cracking technique is also shown to be a versatile tool to form an ultrasmooth surface or a microscale periodic triangular grating structure on the surface, depending on the orientation of the donor substrate used. Strain-induced band gap energy shift is also observed in localized regions of the thin film with a grating structure. The simplicity of this technique, which does not require any sophisticated equipment and complex fabrication process, is promising to reduce the cost of InP thin-film devices.

Because of their lower toxicity, indium phosphide (InP) quantum dots (QDs) are replacing cadmium selenide QDs in applications that require narrowband luminescence across the visible spectrum. Howev...

A 300-GHz quadrature voltage-controlled oscillator (QVCO) integrated with a pair of mixers based on an InP heterojunction bipolar transistor (HBT) technology has been developed. A super-harmonic coupling technique was applied to generate the quadrature signal in the QVCO. The oscillation frequency tuning range is 24.8 GHz (from 286.1 to 310.9 GHz), and the frequency range maintaining the quadrature operation (within ±10°) is 4.8 GHz (297.2–302.0 GHz). The maximum output power of the QVCO was measured as 0.46 dBm at 286.3 GHz. The measured phase noise is −91.4 dBc/Hz with 10 MHz offset at 294.2 GHz. The integrated QVCO-mixer consumes a dc power of 167.5 mW.

This paper reports on a 100-nm gate length InP high-electron-mobility transistor (HEMT) technology for cryogenic low-noise amplifiers (LNAs) with ultra-low power dissipation of $112~\mu \text{W}$ . This result was obtained by using 100-nm gate length InP HEMTs with improved transconductance at low drain current through a scaled-down gate-channel distance while maintaining a low gate leakage current with the use of an InP etch stop layer and Pt gate metal. The noise performance of InP HEMTs was demonstrated in a 4–8 GHz (C–band) three-stage hybrid LNA at the ambient temperature of 5 K. At a dc power dissipation of $300~\mu \text{W}$ , the average noise temperature was 2.8 K with 27 dB gain. At a dc power dissipation of $112~\mu \text{W}$ , the LNA exhibited an average noise temperature of 4.1 K with a gain of 20 dB. The presented results demonstrate the large potential of InP HEMT technology for sub-mW cryogenic LNA design.

We design a lossless $8 \times 8$ Silicon Photonics (SiPh)/Indium Phosphide (InP) hybrid optical switch. The design consists of an 8-channel InP gain block for coupling to an $8 \times 8$ thermally tuned Mach-Zehnder interferometer-based Banyan switch in a passive SiPh platform. The gain block is an array of eight $1300~\mu \text{m}$ -long semiconductor optical amplifiers (SOAs). We experimentally verified the InP gain block while the SiPh chip is accounted by replacing it with a loss component. The SOA in line with the optical signal path provides a net gain larger than 25 dB to compensate for the inherently large insertion loss of the $8 \times 8$ SiPh optical switch. The total energy consumption of the hybrid optical switch in lossless operation mode is 10.44 pJ/bit at 12.5 Gb/s.

The temperature characteristics of arched-cavity quantum-cascade lasers with different geometrical dimensions emitting in the spectral range of 7–8 μm are studied. The laser heterostructure was grown by molecular-beam epitaxy. The active region consisted of 50 cascades based on a heteropair of In0.53Ga0.47As/Al0.48In0.52As solid alloys. Single-mode lasing is demonstrated for lasers with the semicircular cavity segment 100 μm in diameter and the linear segment 1 mm long. The maximum side-mode suppression ratio at a temperature of 290 K was 26 dB, and the emission wavelength was 7.73 μm.

A wideband monolithic microwave/millimeter-wave integrated circuit (MMIC) distributed amplifier (DA) using a 3-D interdigital capacitor at the input of the gain cell is demonstrated in an indium phosphide (InP) heterojunction bipolar transistor (HBT) process. The proposed DA using interdigital capacitors improves the input return loss at high frequencies compared with the one implemented with conventional metal–insulator–metal (MIM) capacitors. The fabricated amplifier achieves a measured average gain of 10.5 dB over a 3-dB bandwidth from 1 to 160 GHz. The maximum measured saturated power ( $P_{\mathrm {sat}}$ ) is 17.8 dBm with the corresponding 1-dB compression power ( $P_{\mathrm {1\,dB}}$ ) of 15 dBm at 55 GHz. The amplifier achieves a minimum $P_{\mathrm {sat}}$ of 14.6 dBm up to 110 GHz.

The method of molecular-beam epitaxy was used to fabricate an elastically balanced heterostructure of a quantum-cascade laser for the spectral range of 4.6 μm based on a heteropair of solid alloys, In0.67Ga0.33As/In0.36Al0.64As, and indium phosphide layers serving as waveguide cladding layers. An X-ray diffraction analysis demonstrated the high uniformity of the composition and thickness of layers in cascades of the heterostructure over the substrate area. Lasers with four cleaved facets show lasing at room temperature at a wavelength close to 4.6 μm with a comparatively low threshold current density of 1.1 kA/cm2.