High-performance selenium doped Sb2S3 based self-powered photodetectors for ultra-low light signals

Abstract

In this study, highly sensitive selenium doped Sb₂S₃ based self-powered photodetectors were produced by using a new coating strategy in the thermal evaporation method. By controlling the amount of selenium, grain boundaries with a diameter of several micrometers were obtained. The photosensitivity of photodetectors with FTO/TiO₂/Sb₂S₃/P3HT/Ag structure reaches up to ∼2.28 × 10⁵ values under visible light. The rise and decay times of the devices are around 0.3 s and have values below 1 s. They show sensitivity even at ultra-low light signals such as ∼0.1 μW/cm², and their specific detectivity reach up to 10¹⁴ Jones. Moreover, the photoresponsivity of these photodetectors reach very high values of 28.22 A/W. According to measurements made under blue, red and green light, the prepared devices are more sensitive to red light. The sensitivity of selenium-doped devices to red light is approximately 12 times that of undoped devices. The results obtained show that these devices can be used effectively in visible light optoelectronic applications.