Photophysical performance of Nd-YAG annealed Pt/n-PSi /Pt photovoltaic photodetectors at different laser energy

Abstract

This study investigates the electrical and photoresponse properties of Nd-YAG annealed Pt/n-PSi/Pt photodetectors. A porous silicon (PSi) layer was deposited on a single crystalline n-type Si via photoelectrochemical etching in aqueous hydrofluoric acid at 45 mA cm−2 for 30 min. Annealing of the n-PSi layer was conducted using a Q-switching Nd:YAG laser at different fluence laser energies (20, 30, 40, 60 mJ cm−2) with a pulse duration of 10 ns. The effect of Nd:YAG laser irradiation on the morphological and structural properties of the deposited n-PSi layer was determined. The n-PSi sample synthesized at 40 mJ cm−2 showed the maximum average discrepancy. The photodetectors fabricated using such materials showed very high sensitivity (1527.9) and low dark current (2.58 × 10−4 A) with an internal photoconductive gain of 16.27, photoresponse of 3.1 A W−1, response time of 0.29 s, and recovery time of 0.45 s. These exceptional properties of the fabricated photodetectors indicate that the laser annealing approach is a viable tool for the synthesis of n-PSi that is suitable for various applications.