Rapid fabrication of fast response CdS/Si visible light photodetector: Influence of laser energy

Abstract

In this article, a series of considerably fast response visible light photodetectors-based CdS nanostructure were fabricated via pulsed laser deposition (PLD) technique. Further, a detailed relation between the utilized laser energy during the nanostructured CdS deposition along with the photo-responsive characteristics of the projected devices was established. Particularly, higher laser energy resulted in augmented figure of merit wherein the photo-responsivity (R) increased from 32 to 54.8 mA/W upon increasing the applied laser energy from 140 to 220 mJ, respectively. The linear dynamic range (LDR) of the fabricated devices exhibited a pronounced laser energy linear dependency with maximum value of 20 dB at 220 mJ. In contrast, the optical power profile revealed an inverse correlation with the attained R, descending values from 68.5 mA/W at 6 mW/cm2 to 34.7 mA/W at 26 mW/cm2. Of the fabricated devices, photodetector attained using laser energy of 220 mJ resulted in response/recovery time of 179 and 161 ms, respectively. Despite the consistency and robustness of the proposed geometry, it represents a rapid framework for eco-friendly optoelectronic design.

Keywords

• Fast response
• Visible light photodetector
• Nanostructured CdS
• Responsivity