Temperature-dependent phase formation of CuInSe2 for self-biased, broadband Si/CuInSe2 heterojunction photodetector

Owing to the numerous applications including optical communication, night vision, remote sensing, and security monitoring, a great interest has emerged in the development of the NIR (near-infrared) photodetectors. In this study, the self-biased Si/CuInSe2 heterojunction photodetectors have been developed and the annealing temperature has been optimized. CuInSe2 thin films have been prepared using the sequential elemental layer deposition followed by annealing at 550, 600, and 650 degrees C. The CuInSe2 annealed at 550 degrees C and 650 degrees C revealed the mixed-phase formation corresponding to CuInSe2 (tetragonal) and Cu7Se4 (Cubic). The CuInSe2 annealed at 600 degrees C confirmed the transition from mixed-phase to single-phase CuInSe2 tetragonal structure. The impact of annealing temperature-dependent phase formation on the optoelectronic characteristics of Si/CuInSe2 heterojunction has been studied. The Si/CuInSe2 heterojunction formation and photodetection in the self-biased mode have been investigated under varying Halogen light intensity and wavelength-dependent light. The highly sensitive, broadband spectral response and enhanced detectivity in the self-biased mode have been explored in the vicinity of varying annealing temperatures. The optimum Si/CuInSe2 heterojunction photodetector performance was achieved at 600 degrees C possessing the sensitivity, detectivity, and LDR up to 2.4x10(3), 0.05x10(12) Jones, and 68 dB under Halogen light exposure and 0.8x10(4), 0.55x10(12) Jones and 79 dB under 980 nm light. The present study provides useful insight into the Si/CuInSe2 heterojunction development as an optoelectronic device providing the correlation between the fundamental characteristics of CuInSe2 and its development as a broadband photodetector possessing excellent device performance in the NIR range. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, self-biased Si/CuInSe2 heterojunction photodetectors were developed and optimized through annealing temperature control. The influence of annealing temperature on phase formation and optoelectronic characteristics of the Si/CuInSe2 heterojunction was investigated. The performance of the photodetector was analyzed under varying Halogen light intensity and wavelength-dependent light. The study demonstrated the potential of Si/CuInSe2 heterojunctions as broadband photodetectors with excellent device performance in the NIR range.