LAUSR

Owing to its high photosensitivity and excellent optoelectrical properties in the visible range, the TlInSSe single crystal is considered for use in high performance visible photodetectors. Herein, we report a detailed optoelectrical investigation of TlInSSe single crystal grown via the Bridgman technique. The photocurrent was observed to increase with an increase in the illumination intensity. The temperature-dependent photoconductivity under different illumination intensities was studied to understand the photogenerated charge transport mechanism in the TlInSSe crystal. A drop in activation energy was noticed from 0.278 eV (under dark conditions) to 0.114 eV (under illumination), attributed to the filling of trap states by photogenerated carriers. The photo-switching behavior was studied and the growth and decay times were found to be ~310 and 300 ms, respectively. The photodetector device of the grown crystal was fabricated and the important figure of merit was determined for 532 nm laser light. The photodetector exhibits a responsitivity up to 0.61 A W−1, a detectivity up to 6.24 × 1011 Jones, and an external quantum efficiency up to 120%. These parameters decrease with an increase in the illumination intensity, but increase with applied voltage. These excellent optoelectrical properties make TlInSSe single crystal a highly competitive candidate for visible photodetector devices.