Photoluminescence (PL) steady-state spectra of p-ZnGeP2 (ZGP) single crystals grown by high- and low-temperature directed crystallization have been investigated. It is determined that the long-wavelength component PL with a maximum in the interval 1.2–1.5 eV for different crystals quenched in the temperature range 77–300 K. The long-wavelength component PL are due to donor-acceptor pair transitions. At room temperature the short-wavelength PL with a maximum near 1.85 eV becomes the determining component. The nature of this band discussed. The use of low-temperature directed crystallization reduces the concentration of lattice defects in ZGP single crystals and opens up the new possibilities for increasing the conversion efficiencies of nonlinear devices.

The inelastic light scattering spectra of chalcopyrite structure ZnGeP2 crystals grown by an improved low temperature crystallization from the nonstoichiometric solution of this compound in the liquid Bi or liquid Tl solutions as well as grown by high temperature Bridgman technique has been investigated together with the optical absorption and electron transport measurements.