Photoluminescence Studies of HgCdTe Epilayers

Abstract

We studied the photoluminescence of Hg1−xCdxTe (x ≈ 0.3) layers grown by molecular-beam epitaxy on CdZnTe. The investigations were carried out on unintentionally doped, In-doped, and As-doped samples, and the effect of different annealing procedures was examined. Excitation-power-dependent and temperature-dependent comparative studies were performed. The transition mechanisms are discussed, and optical signatures for arsenic site transfer are found. The contributions due to As2Te3, As in an amphoteric site, Hg vacancies, and AsHg complexes were identified, and their ionization energies measured. The results are consistent with results found by other techniques. Thus, it is shown that photoluminescence applied to Hg1−xCdxTe can resolve characteristics corresponding to native and intentional donors/acceptors, and offers a nondestructive, fast tool for material characterization.