Effect of etching time on characterizations of porous silicon passivated by a nano-silver layer

Abstract

Abstract Porous silicon (PS) is a candidate for silicon-based optoelectronic applications. This paper presents the effect of etching time on the properties of PS deposited by a nano-thin film of a silver layer (10 nm Ag/PS) using radio frequency (RF)-sputtering technique at room temperature (RT). The PS was prepared by electrochemical etching (ECE) method for n-type (111) Si in an electrolyte solution containing hydrofluoric acid (HF) and ethanol (C2H6O) at a volume ratio of 1:4 with a direct current of 10 mA for different etching duration (30, 45, and 60 min). Structural, surface, and optical characterizations of the samples were carried out by using field emission scanning electron microscopy (FESEM), energy dispersive X-rays (EDX), X-ray diffraction (XRD), UV–Vis spectrophotometer, and photoluminescence (PL) spectroscopy. The results show that the sample prepared for 30 min demonstrated enhancement in the PL and reflectivity spectra compared to other samples which indicate a higher etching rate and a thinner wall between the pores on the surface over a larger exposed area was obtained.