Photoluminescence (PL) studies were carried out on CuAlS2 heteroepitaxial layers grown by low-pressure metalorganic chemical vapor deposition. The epilayers exhibited an intense near-band-edge PL peak at 3.525 eV (77 K) in the ultraviolet (UV) wavelength region together with PL bands at 2.76 and 2.1 eV. This near-band-edge PL peak showed the following properties: (i) the PL was strongly polarized parallel to the c axis, (ii) the peak energy varied from 3.497 to 3.525 eV at 77 K with increasing epilayer thickness from 0.49 to 0.67 μm, and (iii) the emission was observed up to room temperature. This UV-PL was tentatively assigned to an exciton-related emission, energy shifted due to the residual lattice strain.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)