Resonant photoluminescence measurements in As- and P-doped ZnTe epilayers

Abstract

The near-gap photoluminescence (PL) of MOVPE ZnTe epilayers grown on (0 0 1) GaAs substrates has been extensively studied using resonant-excitation methods. Heteroepitaxial ZnTe layers show a small biaxial strain which splits excitonic transitions. We obtained the Luttinger parameter γ 1 = 3.8 from transition of the split free exciton 1s and 2s levels. Shallow acceptor states were observed in free standing As- and P-doped ZnTe layers and the Luttinger parameters γ 2 = 0.72 and γ 3 = 1.3 were derived. The magnetic field splitting of the 1S 3 2 acceptor ground state unambiguously identifies the acceptor bound exciton line I 1 a as double light-hole state ( A 0 a1, X 1). Furthermore the magnetic parameters κ A = -0.27 and q A = -0.015 were determined.