Growth of phosphorus-doped ZnTe thin films by molecular beam epitaxy using InP as the dopant source

Abstract

P-doped ZnTe thin films were grown by MBE on ZnTe (100) substrates using InP as the P source under various InP fluxes. Secondary ion mass spectroscopy (SIMS) analyses showed that the P concentration in ZnTe thin films increased with increasing InP flux, although In atoms were also incorporated in the films. To suppress In incorporation, the outlet of the InP cell was modified by mounting a cap and a plate with small holes. As a result, In incorporation was significantly suppressed, resulting in an In concentration three orders of magnitude lower, as confirmed by SIMS, although the P concentration also decreased by almost one order of magnitude compared with the case without a cap. An acceptor-bound exciton (Ia) peak was observed at around 2.36 eV in the P-doped ZnTe thin film grown with a cap, and the Ia intensity increased after annealing, indicating the activation of P acceptors.