Wavelength‐Modulated Absorption Spectra of Pseudodirect Bandgap A²B⁴C Compounds

Abstract

Abstract The wavelength‐modulated absorption spectra of ZnGeP 2 , ZnSiAs 2 , ZnSiP 2 , and CdSiP 2 chalcopyrite crystals have been investigated with polarized light in the region of the absorption edge at 77 and 300 °K. Structures due to the pseudodirect optical transitions derived from indirect ones in sphalerite have been observed. The valence band structure and the relative location of the energy levels in the conduction band of the pseudodirect‐band gap A 2 B 4 C compounds have been determined.