Te<sub><i>x</i></sub>Se<sub>1-<i>x</i></sub> Shortwave Infrared Photodiode Arrays with Monolithic Integration.

Peng, Meng; He, Yuming; Hu, Yuxuan; Liu, Zunyu; Chen, Xinyi; Liu, Zhiqiang; Yang, Junrui; Chen, Maohua et al. · Nano Lett · 2024

basic_science · Level V

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Abstract

Te<sub><i>x</i></sub>Se<sub>1-<i>x</i></sub> shortwave infrared (SWIR) photodetectors show promise for monolithic integration with readout integrated circuits (ROIC), making it a potential alternative to conventional expensive SWIR photodetectors. However, challenges such as a high dark current density and insufficient detection performance hinder their application in large-scale monolithic integration. Herein, we develop a ZnO/Te<sub><i>x</i></sub>Se<sub>1-<i>x</i></sub> heterojunction photodiode and synergistically address the interfacial elemental diffusion and dangling bonds via inserting a well-selected 0.3 nm amorphous TeO<sub>2</sub> interfacial layer. The optimized device achieves a reduced dark current density of -3.5 × 10<sup>-5</sup> A cm<sup>-2</sup> at -10 mV, a broad response from 300 to 1700 nm, a room-temperature detectivity exceeding 2.03 × 10<sup>11</sup> Jones, and a 3 dB bandwidth of 173 kHz. Furthermore, for the first time, we monolithically integrate the Te<sub><i>x</i></sub>Se<sub>1-<i>x</i></sub> photodiodes on ROIC (64 × 64 pixels) with the largest-scale array among all Te<sub><i>x</i></sub>Se<sub>1-<i>x</i></sub>-based detectors. Finally, we demonstrate its applications in transmission imaging and substance identification.