Electrodeposition of Te onto monocrystalline n- and p-Si(1 0 0) wafers

Abstract

Electrochemical deposition of Te onto n- and p-Si(1 0 0) wafers from 0.1 M HNO 3 + 1 mM TeO 2 solution was studied using cyclic voltammetry (CV), chronoamperometry, ex situ SEM and XRD. Electrodeposition of Te onto n-Si takes place both in the dark and under illumination. Electrodeposition of Te onto p-Si proceeds only under illumination, when the photoelectrons are generated in silicon substrate and reduce Te(IV) species in solution. Electrochemical reduction of Te(IV) on n- and p-Si occurs with large cathodic overvoltage (0.22–0.62 V). Nucleation of Te on n- and p-Si proceeds via 3D island growth, it is characterised correspondingly by progressive and instantaneous nucleation mechanisms followed by diffusion limited growth. Cathodic deposition of Te onto n- and p-Si is irreversible. Anodic stripping of Te electrodeposited onto p-Si occurs both in the dark and under illumination and anodic stripping of Te from n-Si proceeds only under illumination.