Application of the difference spectroscopy for studying of complex acceptors in CdTe

Wavelength modulation of the excitation source combined with the analysis of the differential PL signal have been applied to studying of electronic spectra of acceptors in compensated CdTe:Cl, CdTe:Ag,Cl single crystals. For the Cl-related complex acceptor with an activation energy of ∝121 meV (A-center), the energies of eight excited states are measured. In the case of tetrahedral Ag_Cdacceptor the splitting of 2P_3/2 (Γ₈) and 2S_3/2 (Γ₈) states has been revealed for Ag_Cd centres located at a short distances (5-7 nm) from a hydrogen-like donor (Cl_Te). A method allowing a simple symmetry test for acceptors in a diverse zinc-blende compound semiconductor is proposed. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)