Fast Uncooled Mid‐Wavelength Infrared Photodetectors with Heterostructures of van der Waals on Epitaxial HgCdTe

Abstract

Uncooled infrared photodetectors have evoked widespread interest in basic research and military manufacturing because of their low‐cost, compact detection systems. However, existing uncooled infrared photodetectors utilize the photothermoelectric effect of infrared radiation operating at 8–12 µm, with a slow response time in the millisecond range. Hence, the exploration of new uncooled mid‐wavelength infrared (MWIR) heterostructures is conducive to the development of ultrafast and high‐performance nano‐optoelectronics. This study explores a van der Waals heterojunction on epitaxial HgCdTe (vdWs‐on‐MCT) as an uncooled MWIR photodetector, which achieves fast response as well as high detectivity for spectral blackbody detection. Specifically, the vdWs‐on‐MCT photodetector has a fast response time of 13 ns (77 MHz), which is approximately an order of magnitude faster than commercial uncooled MCT photovoltaic photodetectors. Importantly, the device exhibits a photoresponsivity of 2.5 A W‐1, quantum efficiency as high as 85%, peak detectivity of 2 × 1010 cm Hz1/2 W‐1 under blackbody radiation at room temperature, and peak detectivity of up to 1011 cm Hz1/2 W‐1 at 77 K. Thereby, this work facilitates the effective design of high‐speed and high‐performance heterojunction uncooled MWIR photodetectors.

High-sensitivity CdTe phototransistors with the response spectrum extended to 1.65 μm

“…For instance, at 1.45 μm wavelength, R , D * and EQE reach 10.2 A W −1 , 9.3 × 10 11 Jones and 870% with the gate of 20 V, respectively. These characteristic parameters are comparable to 0.84 A W −1 R and 1.02 × 10 11 Jones D * for the Ge, R (1.03 A W −1 ) and D * (2.93 × 10 12 Jones) for the InGaAs, and D * (10 9 Jones) of SWIR MCT commercial photodetectors, 23,39 novel WSe 2 /SnSe 2 (ref. 40) ( R : 80 A W −1 , D *: 1.4 × 10 10 Jones), graphene/MCT ( R : 2.6 A W −1 , D *: 1.45 × 10 12 Jones) heterostructure detectors, 41 and much superior to those of R (0.0518 A W −1 ) and D * (1.38 × 10 10 Jones) of graphene/Ge, 24 R (0.4 A W −1 ) and D * (2 × 10 8 Jones) of the graphene/Si photodetector.…”

Room-Temperature Blackbody-Sensitive and Fast Infrared Photodetectors Based on 2D Tellurium/Graphene Van der Waals Heterojunction

“…The expected output characteristic curve is related to these narrow band gap materials with high carrier concentrations. 30 Under 1550 nm laser irradiation, a short-circuit current and an opencircuit voltage can be seen in the output characteristic curve, as shown in the inset of Figure 2a, which proves that the device can work in the PV mode. Furthermore, photocurrent mappings of tellurium/graphene devices at the wavelength of 1550 nm were achieved to further clarify the operation mechanism, as shown in Figure 2b.…”

“…Figure a demonstrates the current–voltage ( I – V ) characteristic curve of the tellurium/graphene heterojunction infrared detector measured at room temperature. The expected output characteristic curve is related to these narrow band gap materials with high carrier concentrations . Under 1550 nm laser irradiation, a short-circuit current and an open-circuit voltage can be seen in the output characteristic curve, as shown in the inset of Figure a, which proves that the device can work in the PV mode.…”

Strain-durable dark current in near-infrared organic photodetectors for skin-conformal photoplethysmographic sensors

“…Development of high-detectivity near-infrared photodetectors (NIR PDs) have received significant attention in recent years because of their diverse applications including NIR image sensors, thermal detectors, biomedical sensors, and telecommunication devices ( Liu et al., 2021a , 2021b ; Li et al., 2019a ; Meng et al., 2021 ; Chow and Someya, 2020 ). For demonstrating high-performance NIR PDs, various types of low-bandgap inorganic semiconductors absorbing long wavelengths lights, such as Si, GaAs, InSb, HgCdTe, and CdZnTe, have been developed ( Lu et al., 2018 ; Wang et al., 2021 ; Li et al., 2016 ; Shkir et al., 2019 ; Zhang et al., 2020 ). Despite their applicability as NIR sensitizers, NIR PDs based on these materials suffer from fabrication complexity, high-cost process, inherent low absorption coefficient, and low mechanical flexibility ( Michel et al., 2010 ; Chen et al., 2016 ).…”