Formation of silver nanoparticles and their application for suppressing surface reflection of n-type silicon

Ngan Le Nguyen, Thi Cam Hue Phan, Thi My Dung Dang and Mau Chien Dang

Abstract

In this paper silver-assisted chemical etching (SACE) was studied to increase roughness and reduce light reflection from the surface of n-type (100) mono-crystalline silicon. SACE process includes two basic steps which are silver deposition and chemical etching step. Simple electroless silver deposition step using mixture of AgNO₃ and HF was utilized to form silver nanoparticles onto n-type silicon surface. Following chemical etching step was carried out by immersing samples in mixture of HF and H₂O₂. Concentration of AgNO₃ in eletroless deposition step and concentration of HF in chemical etching step were investigated to get minimum reflectance. The surface of sample was characterized by scanning electron microscopy (SEM), field emission scanning electron microscopy (FE-SEM) and sample reflectance was measured at the wavelength range from 350–1100 nm. The results show that reflectance depends on AgNO₃ concentration in electroless deposition step and HF concentration in etching step and the minimum solar-weighted reflectance is 1.74%. This method can be considered as simple, inexpensive method to effectively increase roughness and suppress light reflection for photovoltaic, optoelectronic, sensor, photonic applications