A high resolution investigation of the recombination radiation from Si containing the acceptors B, Al, Ga, In and Tl

Abstract

A high resolution investigation has been made of the luminescence from Si doped with the acceptors B, Al, Ga, In and Tl in the spectral energy range 0.96–1.16 eV using 50 keV electron excitation. Luminescence from Tl-doped material has not previously been reported. Particular attention is directed to the splitting of the no-phonon and phonon-assisted bound exciton lines which has been detected for the first time in luminescence studies. Thermalizing doublet structure has been observed for Al, Ga and In-doped Si and a thermalizing triplet structure for tl-doped material, and three possible models for the fine structure are considered. Satellite lines on the low energy side of the bound exciton lines, which have previously only been observed in B, P and Li-doped Si and attributed to multiple bound exciton complexes, are reported for Al and Ga-doped material. Recent models for these lines are discussed together with their relationship with electron-hole droplet condensation. Structure associated with free electron to bound hole transitions are reported and discussed.