scholarly journals High-performance HgCdTe avalanche photodetector enabled with suppression of band-to-band tunneling effect in mid-wavelength infrared

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Jin Chen ◽  
Jian Chen ◽  
Xin Li ◽  
Jiale He ◽  
Liao Yang ◽  
...  
Keyword(s):  
Dark Current ◽  
High Performance ◽  
Single Photon ◽  
Avalanche Photodiodes ◽  
Tunneling Effect ◽  
Single Element ◽  
Transport Mechanisms ◽  
Competitive Mechanism ◽  
High Consistency ◽  
Dark Currents

AbstractHgCdTe avalanche photodiodes promise various fascinating applications due to the outstanding capability of detecting weak signals or even single photon. However, the underlying transport mechanisms of diverse dark current components are still unresolved at high reverse bias, thus limiting the development of high-performance devices. Here, we establish an accurate model to demonstrate the competitive mechanism between band-to-band and avalanche dark currents in positive-intrinsic-negative structures. Based on the high consistency between the simulated and measured results, we find that both components jointly dominate overall dark current but with a larger avalanche current. This breaks the conventional cognition that band-to-band dark current contributes the majority. With the guidance, we reconstruct an optimized device and achieve gain 1876 (6153) and dark current 10−10 (10−9) A at bias −10 (−10.5) V, respectively. Comparisons of dark current and gain with reported single-element devices further confirm the outstanding performance of our device.

Dark currents of unipolar barrier structures based on mercury cadmium telluride for long-wave inred detectors

2021 ◽  
pp. 3-8
Author(s):  
A.V. Voitsekhovskii ◽  
◽  
S.N. Nesmelov ◽  
S.M. Dzyadukh ◽  
S.A. Dvoretsky ◽  
...  
Keyword(s):  
Cadmium Telluride ◽  
Leakage Current ◽  
Current Density ◽  
Dark Current ◽  
Mercury Cadmium Telluride ◽  
Current Component ◽  
Long Wave ◽  
Dark Currents ◽  
Surface Leakage ◽  
Long Wave Infrared

Two types of long-wave infrared nBn structures based on mercury cadmium telluride grown by molecular beam epitaxy on GaAs (013) substrates have been fabricated. For each type of device, the side walls of the mesa structures were passivated with an Al2O3 dielectric film or left without passivation. The CdTe content in the absorbing layers was 0.20 and 0.21, and in the barrier layers, 0.61 and 0.63. The dark currents of the manufactured devices were studied in a wide range of voltages and temperatures. The values of the surface leakage component are found under various conditions. It has been shown that the surface leakage current density decreases upon passivation with an Al2O3 film. It was found that at room temperature in the fabricated nBn structures with reverse biases, the surface leakage component dominates, and with forward biases, the dark current is determined by the combined effect of the surface leakage component and the bulk current component. From the Arrhenius plots, the values of the activation energies of the surface leakage current component were found, which at small reverse biases are in the range from 0.05 to 0.10 eV. At small reverse biases, upon cooling the samples, the role of the bulk component of the dark current increases, which at 180 K is approximately 0.81 A/cm2. In the temperature range 200-300 K, the values of the dark current density exceed the values calculated according to the empirical Rule07 model by a factor of 10-100, which indicates the possibility of creating long-wave infrared barrier detectors with a decrease in the values of the surface leakage component.

scholarly journals Development of Low-Cost Fast Photoacoustic Computed Tomography: System Characterization and Phantom Study

2019 ◽  
Vol 9 (3) ◽  
pp. 374 ◽  
Author(s):  
Mohsin Zafar ◽  
Karl Kratkiewicz ◽  
Rayyan Manwar ◽  
Mohammad Avanaki
Keyword(s):  
Computed Tomography ◽  
Spatial Resolution ◽  
Temporal Resolution ◽  
High Performance ◽  
Low Cost ◽  
Single Element ◽  
Tomography System ◽  
System Characterization ◽  
2D Images ◽  
Fast Rotating

A low-cost Photoacoustic Computed Tomography (PACT) system consisting of 16 single-element transducers has been developed. Our design proposes a fast rotating mechanism of 360o rotation around the imaging target, generating comparable images to those produced by large-number-element (e.g., 512, 1024, etc.) ring-array PACT systems. The 2D images with a temporal resolution of 1.5 s and a spatial resolution of 240 µm were achieved. The performance of the proposed system was evaluated by imaging complex phantom. The purpose of the proposed development is to provide researchers a low-cost alternative 2D photoacoustic computed tomography system with comparable resolution to the current high performance expensive ring-array PACT systems.

High-performance integrated pick-up circuit for SPAD arrays in time-correlated single photon counting

2017 ◽  
Author(s):  
Giulia Acconcia ◽  
Alessandro Cominelli ◽  
Pietro Peronio ◽  
Ivan Rech ◽  
Massimo Ghioni
Keyword(s):  
High Performance ◽  
Single Photon ◽  
Photon Counting ◽  
Single Photon Counting

scholarly journals Low dark current and high gain-bandwidth product of avalanche photodiodes: optimization and realization

2020 ◽  
Vol 28 (11) ◽  
pp. 16211
Author(s):  
Hui Wang ◽  
Xiaohong Yang ◽  
Rui Wang ◽  
Tingting He ◽  
Kaibao Liu
Keyword(s):  
Dark Current ◽  
Avalanche Photodiodes ◽  
High Gain ◽  
Gain Bandwidth

scholarly journals Low Dark Current and Performance Enhanced Perovskite Photodetector by Graphene Oxide as an Interfacial Layer

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 190
Author(s):  
Ali Hassan ◽  
Muhammad Azam ◽  
Yeong Hwan Ahn ◽  
Muhammad Zubair ◽  
Yu Cao ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Dark Current ◽  
High Performance ◽  
Carrier Transport ◽  
Defect Density ◽  
Low Cost ◽  
Degradation Process ◽  
Device Performance ◽  
Interface Engineering ◽  
Defect Passivation

Organic–inorganic hybrid perovskite photodetectors are gaining much interest recently for their high performance in photodetection, due to excellent light absorption, low cost, and ease of fabrication. Lower defect density and large grain size are always favorable for efficient and stable devices. Herein, we applied the interface engineering technique for hybrid trilayer (TiO2/graphene oxide/perovskite) photodetector to attain better crystallinity and defect passivation. The graphene oxide (GO) sandwich layer has been introduced in the perovskite photodetector for improved crystallization, better charge extraction, low dark current, and enhanced carrier lifetime. Moreover, the trilayer photodetector exhibits improved device performance with a high on/off ratio of 1.3 × 104, high responsivity of 3.38 AW−1, and low dark current of 1.55 × 10−11 A. The insertion of the GO layer also suppressed the perovskite degradation process and consequently improved the device stability. The current study focuses on the significance of interface engineering to boost device performance by improving interfacial defect passivation and better carrier transport.

scholarly journals Optimizing the stoichiometry of ultrathin NbTiN films for high-performance superconducting nanowire single-photon detectors

2019 ◽  
Vol 27 (19) ◽  
pp. 26579 ◽  
Author(s):  
Julien Zichi ◽  
Jin Chang ◽  
Stephan Steinhauer ◽  
Kristina von Fieandt ◽  
Johannes W. N. Los ◽  
...  
Keyword(s):  
High Performance ◽  
Single Photon ◽  
Photon Detectors ◽  
Single Photon Detectors ◽  
Superconducting Nanowire
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