A5101842776- Semiconductor Quantum Structures and Devices
- Advanced Semiconductor Detectors and Materials
- Advanced Optical Sensing Technologies
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Quantum Dots Synthesis And Properties
- Nanowire Synthesis and Applications
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Photocatalysis Techniques
- GaN-based semiconductor devices and materials
- Spectroscopy and Laser Applications
- Thermography and Photoacoustic Techniques
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Copper-based nanomaterials and applications
- TiO2 Photocatalysis and Solar Cells
- Semiconductor materials and interfaces
- Organic Light-Emitting Diodes Research
- Radiation Detection and Scintillator Technologies
- Radar Systems and Signal Processing
- Advanced Fiber Laser Technologies
- Optical Coatings and Gratings
- Perovskite Materials and Applications
- ZnO doping and properties
- Engineering Applied Research
- Fuel Cells and Related Materials
The Ohio State University
2006-2024
The University of Texas at Arlington
2024
Yeungnam University
2015-2018
Government of the Republic of Korea
2018
High sensitivity avalanche photodiodes (APDs) operating at eye-safe infrared wavelengths (1400–1650 nm) are essential components in many communications and sensing systems. We report the demonstration of a room temperature, ultrahigh gain ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>M</mml:mi> <mml:mo>=</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mn>278</mml:mn> </mml:mrow> </mml:math> , <mml:mi>λ</mml:mi> <mml:mn>1550</mml:mn> <mml:mspace...
The short-wave infrared (SWIR) wavelength, especially 1.55 μm, has attracted significant attention in various areas such as high-speed optical communication and LiDAR systems. Avalanche photodiodes (APDs) are a critical component receiver these systems due to their internal gain, which enhances the system performance. Silicon-based APDs promising since they CMOS compatible, but limited detecting μm light detection. This study proposes p-type Si on n-type GaAs0.51Sb0.49 (GaAsSb) lattice...
We demonstrate low noise random alloy (RA) Al0.85Ga0.15AsSb (hereafter AlGaAsSb) avalanche photodiodes (APDs) nearly lattice-matched to InP substrates. In contrast digital (DA), RAs are manufacturable due the ease of growth. The 910 nm-thick RA AlGaAsSb was grown at a temperature around 450 °C mitigate phase separation by suppressing surface mobility adatoms. high quality material verified x-ray diffraction, Nomarski, and atomic force microscope images. Capacitance–voltage measurement found...
Low noise avalanche photodiodes (APDs) detecting 1550 nm wavelength play a crucial role in optical communication and LiDAR systems. These APDs utilize separate absorption, charge, multiplication (SACM) architecture with an absorber for 1400–1650 detection low noise, high gain multiplier that can be independently optimized signal-to-noise ratio. Recently, GaAs0.5Sb0.5/Al0.85Ga0.15As0.56Sb0.44 SACM have demonstrated ultra-high extremely possibly improving sensitivity over Si InGaAs/InP...
High-sensitivity avalanche photodiodes (APDs) are used to amplify weak optical signals in a wide range of applications, including telecommunications, data centers, spectroscopy, imaging, light detection and ranging, medical diagnostics, quantum applications. This paper reports antimony-based separate absorption, charge, multiplication structure APDs on InP substrates. Al0.7In0.3As0.79Sb0.21 is for the multiplier region, InGaAs as absorber. The excess noise comparable that silicon APDs;...
The rising concentration of greenhouse gases, especially methane and carbon dioxide, is driving global temperature increases exacerbating the climate crisis. Monitoring these gases requires detectors that operate in extended short-wavelength infrared range (~2.4 µm), covering (1.65 µm) dioxide (2.05 wavelengths. Here, we present a high-performance linear mode avalanche photodetector (APD) with an InGaAs/GaAsSb type-II superlattice absorber AlGaAsSb multiplier, matched to InP substrates. This...
In this paper, we report a low-loss photonic integrated circuits (PICs) platform at blue wavelengths of the visible spectral regime. Silicon nitride (SiN) is popular passive waveguide material due to its fabrication flexibility, CMOS compatibility and transparency in wavelength For active devices including lasers, gallium (GaN) alloys are considered. Several basic building blocks for development complete platform, diode in-plane- out-of-plane light couplers, as well on-and off-chip coupling...
Al0.85Ga0.15As0.56Sb0.44 has recently attracted significant research interest as a material for 1550 nm low-noise short-wave infrared (SWIR) avalanche photodiodes (APDs) due to the very wide ratio between its electron and hole ionization coefficients. This work reports new experimental excess noise data thick PIN NIP structures, measuring low at significantly higher multiplication values than previously reported (F = 2.2 M 38). These results disagree with classical McIntyre theory, which...
For short-wavelength infrared (SWIR) avalanche photodiodes, a separate absorption, charge, and multiplication design is widely used. AlInAsSb on an InP substrate potential layer with lattice match to absorber candidates across the SWIR. Our new measurements demonstrate that promising multiplier candidate relatively low dark current density of 10−4 A/cm2 at gain 30; high gain, measured up 245 in this study; large differentiation electron hole ionization leading excess noise, be 2.5 30. These...
Electrically-pumped AlGaN-based edge-emitting laser diodes with a buried tunnel junction (TJ) for sub-300 nm emission are designed in this paper. Hole injection is one of the major concerns design ultraviolet (UV) lasers based on material system. The use low-resistive TJ as an intracavity contact within devices will offer opportunity to replace highly resistive p-type cladding and layers by their n-doped counterparts. This advanced polarization-engineered interband TJs lead improved hole...
We provide an overview of our progress on the development linear mode avalanche photodiodes (LmAPDs) InP substrates using antimony (Sb)-based multipliers for short-wavelength infrared (SWIR) spectral region. identify key figures merit LmAPDs to higher sensitivity and speed applications like light detection ranging (LiDAR) remote sensing. discuss design separate absorption, charge, multiplication (SACM) APDs that are used narrow gap absorption. summarize results impact ionization, gain, dark...
The performance of the photodetector is often primary limiting factor affecting a free space communication or LiDAR system's sensitivity. Avalanche photodiodes (APDs) can be used to improve signal noise ratio (SNR) compared conventional <i>p-i-n</i> photodiodes. Our study focuses on demonstrating an APD operating in eye-safe short-wave infrared (SWIR) spectrum (>1400 nm) with high multiplication (<i>M</i>>1200) and low excess (<i>F</i><7 at <i>M</i>=200) room temperature. This...
Polyvinylidene fluoride (PVdF) (Kynar 761) nanofibers were prepared by electrospinning at an external voltage of 6-10 kV, a traveling distance 7-15 cm and flow rate 0.4-1 ml/hr. Although the diameter fiber was not significantly changed, conditions affected overall distribution diameter. This is probably due to interactions, both attraction repulsion, positive charges on polymer solutions electrically grounded collector. Especially, effect investigated in this study. The final PVdF nanofiber...
Highly increased photocurrent response of unbalanced RF magnetron sputtered TiO<sub>2</sub> thin film on ITO-coated patterned SiO<sub>2</sub> nanocone arrays.
Photonic integration of GaN and Si-SiN platforms at the shortest visible wavelength is reported. Maximum theoretical coupling efficiencies up to 51% 24% for a vertical grating coupler (fiber-chip) hybrid integration, respectively, are achieved.
We present gain, dark current and excess noise characteristics of PIN Al<sub>0.85</sub>Ga<sub>0.15</sub>As<sub>0.56</sub>Sb<sub>0.44</sub> (hereafter AlGaAsSb) avalanche photodiodes (APDs) on InP substrates with 1000 nm thick multiplier layers. The AlGaAsSb APDs were grown by molecular beam epitaxy using a digital alloy technique (DA) to avoid phase separation. Current-voltage measurements give peak gain ~ 42, breakdown voltage – 54.3 V, density at 10 145 μA/cm<sup>2</sup>. Excess...
Avalanche photodiodes (APDs) are critical components for a variety of remote sensing applications, particularly 3D imaging using light detection and ranging (LiDAR). APDs can provide higher sensitivity faster response times than traditional PIN diodes due to their internal gain. To apply LiDAR gas monitoring including greenhouse gases, need be sensitive further into the infrared Si detect. This work investigates an absorber that is 2 μm compatible with APD. A separate absorption, charge,...
Background doping polarity is a critical design parameter for the performance of many optoelectronic devices, including avalanche photodiodes. We have applied technique by using capacitance–voltage (CV) measurements on double mesa structures with p-i-n or n-i-p homojunction to determine background type unintentionally doped intrinsic region. Because CV scale size mesa, they support flexibility in producing variable-sized top and bottom diameters. In this work, we grew, fabricated, tested...
InAs/GaSb 제2형 응력초격자(SLS)를 활성층에 탑재한 [<TEX>$320{\times}256$</TEX>] 초점면 배열(FPA) 적외선 열영상 모듈을 제작하고 열영상을 구현하였다. p-i-n형으로 설계된 소자의 활성층(i) 구조는 300 주기의 [13/7]-ML [InAs/GaSb]-SLS로 구성되어 있고, p와 n 전극층에는 각각 60주기의 [InAs:Be/GaSb]-SLS와 115 [InAs:Si/GaSb]-SLS 구조를 채용하였다. 시험소자의 광반응(PR) 스펙트럼으로부터 피크 파장(<TEX>${\lambda}_p$</TEX>)과 차단 파장(<TEX>${\lambda}_{co}$</TEX>)은 <TEX>${\sim}3.1/2.7{\mu}m$</TEX>과 <TEX>${\sim}3.8{\mu}m$</TEX>이고 180 K 온도까지 동작을 확인하였다. 단위 화소의 간격/메사는 <TEX>$30/24{\mu}m$</TEX> 규격으로 설계되었으며,...
Investigation of surface recombination is an important area for infrared detectors as the demand smaller pixels increases. In this study, we use transient microwave reflectance to characterize minority carrier lifetime InAsSb nBn structures under three conditions: As-Grown, blanket Barrier-Etched, and SU-8 Passivated barrier-etched. A qualitative comparison these samples shows that decreases Barrier-Etched sample compared As-Grown sample, indicating sensitive changes in surface, specifically...
We have demonstrated InGaAs/AlInAsSb separate absorption, charge, and multiplication avalanche photodiodes. The gain, excess noise, temperature-dependent dark current been characterized. APDs were grown on semi-insulating InP substrates, which is beneficial for bandwidth improvement compared to AlInAsSb GaSb substrates.
The application of an electric field to a semiconductor can alter its absorption properties. This electroabsorption effect have significant impact on the quantum efficiency detector structures. photocurrents in bulk InGaAs and GaAsSb p-i-n photodiodes with intrinsic absorber layer thicknesses ranging from 1 4.8 μm been investigated. By using phase-sensitive photocurrent measurements as function wavelength, coefficients low cm−1 were extracted for fields up 200 kV/cm. Our findings show that...
Avalanche photodiodes used for greenhouse gas sensing often use a mesa-structure that suffers from high surface leakage currents and edge breakdown. In this paper, we report 2-micron InGaAs/GaAsSb superlattice (SL) based planar PIN diodes to eliminate the challenges posed by conventional mesa diodes. An alternate way fabricate using atomic layer deposited ZnO was explored effect of diffusion process on studied X-ray diffraction. The optimum conditions were then make diffused Zn concentration...