Te_xSe_1–x Photodiode Shortwave Infrared Detection and Imaging

Abstract

Short‐wave infrared detectors are increasingly important in the fields of autonomous driving, food safety, disease diagnosis, and scientific research. However, mature short‐wave infrared cameras such as InGaAs have the disadvantage of complex heterogeneous integration with complementary metal–oxide–semiconductor (CMOS) readout circuits, leading to high cost and low imaging resolution. Herein, a low‐cost, high‐performance, and high‐stability TexSe1–x short‐wave infrared photodiode detector is reported. The TexSe1–x thin film is fabricated through CMOS‐compatible low‐temperature evaporation and post‐annealing process, showcasing the potential of direct integration on the readout circuit. The device demonstrates a broad‐spectrum response of 300–1600 nm, a room‐temperature specific detectivity of 1.0 × 1010 Jones, a −3 dB bandwidth up to 116 kHz, and a linear dynamic range of over 55 dB, achieving the fastest response among Te‐based photodiode devices and a dark current density 7 orders of magnitude smaller than Te‐based photoconductive and field‐effect transistor devices. With a simple Si3N4 packaging, the detector shows high electric stability and thermal stability, meeting the requirements for vehicular applications. Based on the optimized TexSe1–x photodiode detector, the applications in material identification and masking imaging is demonstrated. This work paves a new way for CMOS‐compatible infrared imaging chips.

One-Dimensional Crystal-Structure Te–Se Alloy for Flexible Shortwave Infrared Photodetector and Imaging

“…Considering the non-radiative recombination in Te 0.7 Se 0.3 film and the stress accumulation at the ZnO/Te 0.7 Se 0.3 interface, the thickness of the Te 0.7 Se 0.3 film should not be too thick (Note S3, Supporting Information). The energy band structure of the flexible Te 0.7 Se 0.3 photodiode is shown in Figure b . ZnO is selected as an electron transport layer for its wide energy band gap (∼3.2 eV) and high mobility (∼100 cm 2 V –1 s –1 ). , Considering the amorphous and disordered properties of the as-deposited Te 0.7 Se 0.3 film, annealing is necessary.…”

“…2b. 44 ZnO is selected as an electron transport layer for its wide energy band gap (∼3.2 eV) and high mobility (∼100 cm 2 V −1 s −1 ). 45,46 Considering the amorphous and disordered properties of the as-deposited Te 0.7 Se 0.3 film, annealing is necessary.…”

Flexible Broadband Photodiodes Based on Amorphous Te0.4Se0.6 Thin Films

“…Furthermore, it is important to note that a-Se has an absorption edge at 650 nm and does not exhibit any response to infrared. , It is mainly due to the relatively large optical gap of Se, and the photoresponse range is limited. Hence, tellurium (Te), has been introduced to mix with Se and form alloys, which showed a tunable optical gap down to 0.35 eV. − More recently, short-wavelength infrared (SWIR) photodetectors have been fabricated based on crystalline Te x Se 1– x , but the devices are still suffering from high dark current and low on–off ratio. − Hadar et al also fabricated photovoltaic devices based on Te x Se 1– x showing improved current density and response to the solar spectrum in comparison to pure Se . However, the open-circuit voltage and fill factor of these devices are highly limited by the leakage current caused by the nonuniform morphology, even pinholes formed during the crystallization process.…”

Optimization of a Ge2Sb2Te5-Based Electrically Tunable Phase-Change Thermal Emitter for Dynamic Thermal Camouflage

“…Regulation of thermal radiation has significant application value in fields of infrared detection [1,2], thermal camouflage [3][4][5], radiative cooling [6][7][8], thermophotovoltaics [9][10][11], and thermal management [12,13]. Among these, infrared thermal camouflage, which is capable of shielding a target object from detection by matching the target's thermal radiation to that of its surroundings, has been widely studied [14][15][16][17].…”