Influence of technological defects on the optical and photoelectric properties of AgCd2−xMnxGaSe4 alloys

The study is concerned with the photoelectric and optical properties of a AgCd2−xMnxGaSe4 alloy with a Mn → Cd isovalent substitution. The positions of the photoconductivity and photoluminescence peaks are determined, and the band gap of the alloy is estimated, based on compositional analysis. The influence of technological defects on specific features of the alloy's photoelectric and optical properties is analyzed. It is established that the centers controlling the alloy crystals' photosensitivity are cation vacancies. The photoluminescence centers responsible for emission at awavelengths from 0.77 to 0.88 μm (dependent on the relation between components in the alloy) are defect complexes consisting of cation and anion vacancies. A physically consistent model is proposed to interpret the effects observed in the alloy.