PIN Photodetector Research Articles

AlGaN-Based Ultraviolet PIN Photodetector Grown on Silicon Substrates Using SiN Nitridation Process and Step-Graded Buffers

The integration of aluminum gallium nitride (AlGaN) with silicon substrates attracts significant attention due to the superior UV sensitivity of AlGaN and the cost-effectiveness as well as mechanical robustness of silicon. A PIN ultraviolet photodetector with a peak detection wavelength of 274 nm is presented in this paper. By employing a SiN nucleation layer and a step-graded buffer, a high-quality AlGaN-based photodetector structure with a dislocation density of 2.4 × 109/cm2 is achieved. A double-temperature annealing technique is utilized to optimize the Ohmic contact of the n-type AlGaN. The fabricated UV photodetector attains a dark current of 0.12 nA at −1 V and a peak responsivity of 0.12 A/W.

Implementation of Optical Coherent Communication System between Two Computers

This work represents implementation and investigation of optical coherent communication system between two computers. A single mode optical fiber is selected as transmission medium. The data are sent via the RS-232 standard interface with a bit rate of 9.6 kbps from personal computer (PC1) by line receive to convert the data from electrical levels (-12/+12 V) into TTL level (0/5 V). The modulation of this data was accomplished by internal modulation using laser diode type (HFCT-5208M) 1310 nm wavelength. The optical D-coupler was used to combine the optical signal that come from laser source with optical signal of laser local oscillator (OTS-304XI) at 1310/1550 nm wavelength to obtain coherent (homodyne and heterodyne) detection respectively. A PIN photodetector (HFCT-5208M) is used. Calculations of Signal to Noise Ratio (SNR) and Bit Error Rate (BER) for coherent detection were measured at different length of the optical fiber. Result show that high SNR and low BER for heterodyne detection than for homodyne detection.

Wireless transmission of audio signals and temperature data using an optoelectronic system.

This work presents an optoelectronic instrument designed for wireless visible light communication (WVLC) systems, operating within a wavelength range of 380-750nm and compatible with standard radio frequency (RF) communication. The instrument encompasses two distinct architectures. The first enables the transmission and reception of RF-processed audio signals through a three-stage process involving RF signal transmission via Bluetooth, signal multiplexing using acousto-optic modulation, a sinusoidal grating, a PIN photodetector array, and final audio playback. The second architecture focuses on the wireless transmission and reception of temperature data, utilizing a similar three-stage approach that includes temperature data measurements with an LM35 sensor, signal processing with Arduino UNO microcontrollers, and information transmission via Bluetooth. Experimental results for both architectures validate the effectiveness of this optoelectronic instrument, demonstrating its capability to integrate RF and WVLC technologies.

Extended short-wave infrared high-speed all-GeSn PIN photodetectors on silicon

There is an increasing need for silicon-compatible high-bandwidth extended-short wave infrared (e-SWIR) photodetectors (PDs) to implement cost-effective and scalable optoelectronic devices. These systems are quintessential to address several technological bottlenecks in detection and ranging, surveillance, ultrafast spectroscopy, and imaging. In fact, current e-SWIR high-bandwidth PDs are predominantly made of III–V compound semiconductors and thus are costly and suffer a limited integration on silicon besides a low responsivity at wavelengths exceeding 2.3 μm. To circumvent these challenges, Ge1−xSnx semiconductors have been proposed as building blocks for silicon-integrated high-speed e-SWIR devices. Herein, this study demonstrates vertical all-GeSn PIN PDs consisting of p-Ge0.92Sn0.08/i-Ge0.91Sn0.09/n-Ge0.89Sn0.11 and p-Ge0.91Sn0.09/i-Ge0.88Sn0.12/n-Ge0.87Sn0.13 heterostructures grown on silicon following a step-graded temperature-controlled epitaxy protocol. The performance of these PDs was investigated as a function of the device diameter in the 10–30 μm range. The developed PD devices yield a high bandwidth of 12.4 GHz at a bias of 5 V for a device diameter of 10 μm. Moreover, these devices show a high responsivity of 0.24 A/W, a low noise, and a 2.8 μm cutoff wavelength, thus covering the whole e-SWIR range.

Group-IV based pin photodetectors for C-band application

GeSn photodetectors with Sn contents between 0% and 6.5% were grown pseudomorphically on Ge virtual substrates on Si by molecular beam epitaxy. Based on the similar functional dependence of the current-voltage characteristics, we conclude that a similar crystal defect is the cause of the recombination/generation centers in both the GeSn and the Ge reference sample. We found that dislocations are not the predominant recombination type. The signal-to-background ratio is a proper quantitative measure for the comparison of heterostructure photodetectors and with near zero bias operation in the C-band, the values of around 104 were obtained with 1 mW light input. For C-band operation, the optimal Sn contents are found to be between 2% and 4%.

Heterogeneous Integration for High Performance Electronic and Photonic Devices

In this paper, two representative heterogeneous integrated applications with great performance based on epitaxial layer transfer process are reported. The SiC integrated Si PIN limiter has shown power handling capability of 150W (continues Wave) and 370W (long pulse) at 5.4GHz, which shows outstanding performance than conventional GaAs limiter. While the SiC integrated InP PIN photodetector has shown a high performance of 3-dB bandwidth over 67GHz, and 42% increasing of the optical responsibility over 0.51 A/W compared to the traditional PD. The results verified great potential of transistor level heterogeneous integration for high performance electronic and photonic devices.

InGaAs/Si PIN photodetector with low interfacial recombination rates realized by wafer bonding with a polycrystalline Si interlayer

In this Letter, we proposed a robust InGaAs/Si bonded heterojunction by polycrystalline Si (poly-Si) and amorphous interlayers. The ultra-thin amorphous layer is induced through Ar plasma treatment. The synergism of poly-Si and amorphous interlayers effectively blocks the lattice mismatch and releases the interfacial thermal stress. A bubble- and defect-free bonding interface is achieved even if after annealing at 500 °C, demonstrating compatibility with high-temperature processes. The heavily doped poly-Si interlayer sweeps the electric field from the poly-Si layer and concentrates in the amorphous layer, rendering electron tunneling through the bonding interface and reducing the interfacial recombination rates. As a result, the bonded InGaAs/Si PIN photodetector harvests a saturated and low dark density of 0.26 mA/cm2 at −1 V and a high rectification ratio of 3.5 × 105 at ±1 V. Additionally, the non-optimized device achieves a high responsivity of 0.82 A/W at 1550 nm. These results indicate that the proposed bonding strategy provides a viable route to tackle the electronic, optical, and thermal barriers of integrating single-crystal InGaAs into Si platforms. This enables the photodetection of InGaAs/Si devices with a high signal-to-noise ratio.

Lateral GeSn p-i-n photodetectors on insulator prepared by the rapid melting growth method.

In this work, GeSn lateral p-i-n photodetectors (PDs) on insulator were fabricated with an active GeSn layer grown by the rapid melting growth (RMG) method. Taking advantages of the defect-free GeSn strips, GeSn PDs with 5.3% Sn content have low dark current and high responsivities, which are about 0.48, 0.47, and 0.24 A/W for wavelengths of 1550, 1630, and 2000 nm, respectively. The radio frequency of the lateral GeSn PDs was also studied and a 3 dB bandwidth of about 3.8 GHz was achieved. These results indicate that the GeSn grown by the rapid melting growth method is capable of fabricating high-performance Si-based optoelectronic devices.

High speed broadband light spatial laser system with hybrid linear/parabolic/measured indexed multimode optical fibers performance signature

Abstract This work clarified various multimode fiber configurations with spatial continuous wave lasers based different coding configurations for high speed fiber systems. The optimum lighted power form after linear index multimode fibers versus spectral wavelength is clarified. The optimum lighted form power after parabolic index multimode fibers versus spectral wavelength is demonstrated. The max lighted form power after measured index multimode fibers versus spectral wavelength is illustrated. Optimum lighted form signal power variations after linear index multimode fibers versus time are demonstrated. The max optimum form signal band form power after parabolic index multimode fibers versus time is indicated. The max optimum lighted signal power after measured index multimode fibers versus time is clarified. Total lighted signal power form after linear index multimode fibers is demonstrated. The total lighted signal power form after parabolic index multimode fibers is clarified. Total lighted power signal form after measured index multimode fibers is clarified. Max optimum signal electrical power form amplitude after PIN photodetector based various index multimode fibers is simulated and studied. Total lighted base form power against MMF length for different proposed optical multimode fibers is studied. Signal base band per noise form ratio against MMF length for different base proposed band optical multimode fibers is demonstrated. Total signal form electrical band power against MMF length for different proposed optical multimode fibers is observed. Max Q base band factor form against MMF length for different base band proposed lighted multimode fibers is clarified.

Low dark current lateral Ge PIN photodetector array with resonant cavity effect for short wave infrared imaging

High-performance germanium (Ge) lateral PIN photodetector (PD) arrays for short wave infrared (SWIR) imaging based on Ge-on-insulator (GOI) platform was proposed and demonstrated. The high-quality GOI platform with top-Ge layer thickness of 1.25 μm and threading dislocation density of less than 105 cm−2 was prepared by using bonding and smart-cut technology. P-type and N-type regions with centrosymmetric racetrack shapes were introduced to lower the sidewall electric field and suppress the surface leakage current of the PD. Benefiting from the high-quality of the GOI platform and the unique design of lateral active regions, a low dark current of 2 nA under −1 V with outstanding rectification ratio of 2.1 × 106 were obtained at room temperature. Through constructing a vertical resonant cavity by SiO2 passivation layer and the Si/SiO2 substrate, the responsivity at 1550 nm was enhanced to 0.46 A W−1 with a high specific detectivity of 3.09 × 1010cm·Hz1/2 ·W−1 under −1 V. Ultimately, SWIR imaging was demonstrated by a Ge lateral PIN PD line array with 1 × 8 pixels under zero bias at room temperature. The results indicate that the proposed lateral Ge PD structure holds great application potential in the field of SWIR imaging.

Integrated PIN modulator and photodetector operating in the mid-infrared range from 5.5 μm to 10 μm

Abstract This study reports the experimental demonstration of the first waveguide-integrated SiGe modulator using a PIN diode operating in a wide spectral range of the mid-infrared region. At the wavelength of 10 µm, an extinction ratio up to 10 dB is obtained in injection regime and 3.2 dB in depletion regime. High speed operation is obtained, up to 1.5 GHz. Furthermore, the device can also operate as an integrated photodetector. Photodetection has thus been characterized from 5.2 µm to 10 µm wavelengths showing an internal responsivity around 1 mA/W, and a 3 dB electro-optical bandwidth of 32 MHz. These results show a significant advancement in integrated photodetectors and electro-optical modulators for mid-infrared spectroscopy.

Lightly doped In0.53Ga0.47As/InP SWIR photodetectors with diffusion barrier structure

A diffusion barrier structure is proposed to control the accuracies of the Zinc diffusion velocity and depth for lightly doped short-wave infrared (SWIR) InGaAs planar photodetectors. By employing scanning capacitance microscopy and scanning electron microscopy characterizations, the Zinc diffusion profiles were investigated. The introducing of a moderately doped interlayer effectively tailored the diffusion front with reduced depth. In0.53Ga0.47As/InP PIN photodetectors with different structures were fabricated and characterized. Compared with the typical structure, the barrier detector exhibited a significantly lower dark current as well as an approximately three times higher peak detectivity. These results indicated that the diffusion barrier structure is promising for the fabrication of SWIR InGaAs focal plane arrays with both low capacitance and reduced dark current.

High efficiency coupling fibers with different types of photo detectors for the management of noise multiplication and efficient bandwidth

Abstract This work has clarified the high efficiency coupling fibers with different types of photo detectors for the management of noise multiplication and efficient bandwidth. As well as the study of the base band signal to noise base band form ratios are clarified with EDFA base band amplifier length variations. Max Q form factor with EDFA amplifier base band length variations is also demonstrated. The optimum base band electrical signal form power is simulated with EDFA base band amplifier length variations. The simulative study of Ge and InGaAs PIN photo-detectors performance evaluation are studied in the presence of the soliton transmission fiber systems. The dispersion management by the soliton technique to reach the value around zero. The max base band signal power form is clarified versus time based Ge and InGaAs PIN photo-detectors. Total base band electrical power form based Ge and InGaAs PIN photo-detectors are demonstrated. Max signal base form power amplitude band is simulated with the spectral base band frequency based Ge and InGaAs PIN photo-detectors. The max signal base form power amplitude band is studied versus time based Ge PIN photo-detectors.

AlGaN‐Based Solar‐Blind Ultraviolet Detector with a Response Wavelength of 217 nm

The research of the high Al(x = 0.75) component has always been the focus of the AlGaN solar‐blind ultraviolet (UV) detector. However, due to the lattice and thermal mismatch between the AlGaN and the underlying substrate under existing mainstream heteroepitaxial growth methods, the large density of defects, e.g., point defects, screw dislocations, and edge dislocations, has hindered the performances of AlGaN‐based solar‐blind UV photodetectors. A short superlattice polarization‐induced P‐type doping growth technique is used to fabricate a high‐performance AlGaN‐based back‐illuminated solar‐blind UV p‐i‐n photodetector (PD) fabricated on sapphire substrates. The back‐illuminated AlGaN UV‐PD shows a high external quantum efficiency of 70.2%. The peak responsivity (R) reaches 123 mA W−1 at −5 V with a wavelength of 217 nm. Meanwhile, the dark current density is 2.21 × 10−8 A cm−2. Additionally, the UV/visible rejection ratio for the detectors exceeds four orders of magnitude, and the detectivity (D*) is calculated to be 6.7 × 1012 cm Hz1/2 W−1. The device performance parameters can be attributed to the quality of the epilayer and heterojunctions. This technology provides new ideas for nitride semiconductor materials, further bringing a breakthrough in a wide‐bandgap electronics device.

Efficient employment of Yb doped multi-mode fiber amplifiers based pumped laser with advanced light sources in high speed modulated optical communication systems

Abstract In this work, efficient employment of Yb doped multi-mode fiber amplifiers based pumped laser is simulated with advanced light sources in high speed modulated optical communication systems. The total lighted power through measured index multimode fiber based different base band modulation voltages dual drive MZM measured are clarified. The 3D graph of the mode field intensity distribution through measure index multimode fiber is simulated. Total electrical base ban power form through PIN photo-detector based various modulation voltages Dual drive MZM measured are demonstrated. The max Q form factor-min base band BER values through PIN photo-detector based different modulation voltages dual drive MZM measured are also simulated. The electrical base signal form noise ratio varies is simulated and clarified with modulation voltage based dual drive MZM measure varies. The max Q form base band Factor is demonstrated with modulation voltage based dual drive MZM measure varies. Total lighted base power form varies are clarified with modulation voltage based dual drive MZM measure varies. The different measured index multimode fiber characteristics based spatial VCSEL are also clarified and demonstrated.

Self-powered deep ultraviolet PIN photodetectors with excellent response performance based on Ga2O3 epitaxial films grown on p-GaN

PIN-type self-powered deep ultraviolet (DUV) photodetectors (PDs) based on Ta doped n-Ga2O3/i-Ga2O3/p-GaN structures with different i-Ga2O3 layer thicknesses were prepared. In the structure, a Ta element in the doped Ga2O3 epitaxial layer should be substitutional doping, which can be confirmed by time-of-flight secondary ion mass spectrometry. With increasing thickness (0–90 nm) of the i-Ga2O3 layer, the crystal quality of the deposited epitaxial films is gradually improved, but the performance of corresponding PDs does not increase monotonically. The PD with an i-layer thickness of c.30 nm under zero bias shows the best response performance such as maximum photoresponsivity (8.67 A/W), good detectability (1.08 × 1014 Jones), and fast response/decay time (86/50 ms) under 222-nm-UV-light illumination. Such good performance should be attributed to the competition between the high photogenerated carriers and the low electric field, whereas the competition is caused by broadening of the depletion region. This research provides an improved and easy method for fabricating high-performance self-powered DUV PDs.

On-chip lateral Si:Te PIN photodiodes for room-temperature detection in the telecom optical wavelength bands.

Photonic integrated circuits require photodetectors that operate at room temperature with sensitivity at telecom wavelengths and are suitable for integration with planar complementary-metal-oxide-semiconductor (CMOS) technology. Silicon hyperdoped with deep-level impurities is a promising material for silicon infrared detectors because of its strong room-temperature photoresponse in the short-wavelength infrared region caused by the creation of an impurity band within the silicon band gap. In this work, we present the first experimental demonstration of lateral Te-hyperdoped Si PIN photodetectors operating at room temperature in the optical telecom bands. We provide a detailed description of the fabrication process, working principle, and performance of the photodiodes, including their key figure of merits. Our results are promising for the integration of active and passive photonic elements on a single Si chip, leveraging the advantages of planar CMOS technology.

Filterless and High-Speed InP Near-Infrared Photodetector With an Ultra-Small Full-Width at Half Maximum

Near-infrared narrowband photodetection between 920 and 960 nm is quite appealing for many applications, such as optical communication, security monitoring, and machine vision, owing to the weak photon-scattering effect and the low intensity of sunlight in this range. Herein, a self-powered narrowband InP photodetector is realized based on a junction-controlled charge-collection narrowing (JCCN) mechanism, exhibiting a peak response centered at 954 nm with a full width at half maximum (FWHM) of 17 nm. Thanks to the reflection of the Schottky electrode and the passivation of the Al2O3 layer, the peak specific detectivity of the device can be up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$4.5\times 10^{{11}}$ </tex-math></inline-formula> Jones and a linear dynamic range (LDR) of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim $ </tex-math></inline-formula> 99 dB is achieved under the illumination of 954 nm. Moreover, the device shows long-term stability and excellent repeatability with a −3 dB frequency of 87.3 kHz. Furthermore, unless the wavelength of the background light is in the range of 945–967 nm, the crosstalk value of the device remains below −10 dB. These results signify that the present InP photodetector is a promising building block for future near-infrared optoelectronic systems.

Effect of bubbles at the bonded interface on the performance of GeSn/Si PIN photodetector

Due to the large lattice mismatch between GeSn and Si materials, high-density threading dislocation (TD) forms when GeSn films are grown by epitaxial growth. This leads to the increase of the dark current density (DCD) of the device. The wafer-bonded technique is a promising method to prepare high-quality thin films. This has been used to produce the Si-based GeSn materials with low TDD. However, there are a lot of bubbles at the bonded interface, resulting in the deterioration of the performance of the device. The study of bubbles on the performance of the GeSn PIN photodetector (PD) has not been reported. In this paper, the effects of the bonding bubbles on the performance of the device are performed. The photocurrent, dark current, charge concentration, electric field, and 3dB-bandwidth (BW) as a function of the bubble radius and thickness are demonstrated. The effects of the bubble radius and thickness on the 3dB-BW (∼18 GHz) are insignificant when the bubble thickness and radius are set as 1 nm and 1 μm, respectively. The 3dB-BW decreases to ∼17 GHz when the bubbles are close to the sizes of the top mesa. However, the 3dB-BW drops drastically with the increase of the bubble thickness when the bubble radius reaches 7 μm. Most importantly, the 3dB-BW sharply decreases to ∼30 MHz regardless of the thickness of the bubble when the bubble radius of 14 μm is set. This may provide guidance for the application of the wafer-bonded GeSn PIN PD.

Self-Organized Germanium Quantum Dots/Si3N4 Enabling Monolithic Integration of Top Si3N4-Waveguided Microdisk Light Emitters and p-i-n Photodetectors for On-Chip Sensing

Using a coordinated combination of lithographic patterning and self-assembled growth, Ge spherical quantum dots (QDs) were controllably generated within host layers of Si3N4 as active medium for Si photonics. A significant fabrication advantage of our approach is the high-temperature thermal stability of Ge QDs that are formed by thermal oxidation of poly-SiGe lithographically patterned structures at 800 °C–900 °C, offering flexibility in the waveguide (WG)-material choices, co- design, and integration of Ge photonic devices. Our Ge QDs enable monolithic integration of microdisk light emitters and p-i-n photodetectors (PDs) with top-Si3N4 WG-coupled structures using standard Si processing. Low dark current of 0.3 mA/cm2 at 300 K and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.2\,\mu \text{A}$ </tex-math></inline-formula> /cm2 at 77 K in combination with 3-dB frequency of 12 GHz for Ge-QD PDs and low threshold power of 0.6 kW/cm2 for optically pumped Ge QD/SiN microdisks light emission evidence the high degree of crystallinity of our Ge QDs being an effective building block for 3-D SiN photonic integrated circuits.