▎ 摘　　要

In this research, the intrinsic instability of optical and electrical properties of porous silicon (PS) was minimized by deposition of reduced graphene oxide (rGO). The optoelectrical properties of the devices based on PS substrates showed a lack of stability under prolonged exposure to illumination. Therefore, despite many advantages of PS (e.g. high specific surface area), its application in electronic industries has been hindered. To resolve this problem, a thin layer of rGO was deposited on a bare PS substrate using electrophoretic deposition (EPD) technique. In order to obtain a high-quality porous substrate, the etching time was optimized in electrochemical etching of silicon. The most intense photoluminescence (PL) peak was reported for the sample etched for 20 min which could be due to its high absorption coefficient and large surface area. Moreover, a blue shift was observed in the PL peak position which can be assigned to quantum confinement effect reflecting the minimum crystallite size of this sample. The morphological study of the samples revealed complete coverage of the PS substrate by rGO. After graphene deposition, the PL quenching of PS samples was arrested even under prolonged exposure to laser illumination. For examining the electrical properties, metal-semiconductor-metal photodetectors were fabricated on bare PS and rGO/PS substrates. The results indicated that the photocurrent of the PS sample was diminished under 30-minute exposure to photons. However, the device based on rGO/PS illustrated higher photocurrent stability reflecting that the stability of optoelectrical properties of porous silicon could be enhanced by rGO deposition. (C) 2020 Elsevier B.V. All rights reserved.