Self-driven heterostructure photodetector of sputtered CZTS film on c-Si with an inverted pyramid structure

• Published in: Ceramics international Vol. 48; no. 2; pp. 2105 - 2111
• Main Authors: Lai, Binkang, Shen, Honglie, Zhao, Qichen, Li, Yufang, Fan, Weitao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.01.2022
• Subjects: Decay time; Detectivity; Responsivity; Rise time; Self-driven photodetector; Detectivity; Rise time; Decay time; Self-driven photodetector; Responsivity
• ISSN: 0272-8842; 1873-3956
• DOI: 10.1016/j.ceramint.2021.09.298

Ag has been incorporated into the CZTS film through post-doping by magnetron sputtering to decrease the CuZn anti-site defect. Efforts have been dedicated to optimize the Ag sputtering time and 60 s will be the best as surveyed from the SEM, XRD and Raman spectra. Then the broad-band self-driven heterostructure photodetector has been manufactured by combining the CZTS and inverted pyramid n-Si (IP n-Si). The device represents the first-rank property under the irradiation of 5 mW, 780 nm LED with 0 V bias with the responsivity and detectivity of 7.2 mA/W and 4.98 × 1010 Jones respectively. The device can persist excellent linearity when enduring a 40 mW-80 mW, 980 nm NIR laser with 0 V bias. The comprehensive performance becomes the best under the irradiation of a 50 mW laser. The responsivity and detectivity are 1.22 mA/W and 1.98 × 1010 Jones. The device can also work stably as the laser changes from 1 Hz to 15 kHz. The rise time and decay time are 93.3 μs and 141.0 μs respectively. These results open up an innovative application for CZTS to build a broad-band self-driven photodetector as a window-layer. Then we irradiate the device with a 980 nm infrared laser, the bias voltage is still 0 v, but the power of the irradiation is changed from 40 w to 80 w to study the stability of the device under different light intensities, and whether it can maintain good linear characteristics.