Photoluminescence Compounds ZnGa₂Se₄ and ZnGa₂Se₄: Eu²⁺

Abstract

Photoluminescence (PL) spectra measurements have been carried out in the ternary chalcopyrite semiconductor compounds ZnGa 2 Se 4 2Se 4 : Eu 2+ using single-wavelength excitation of a Hg lamp with λ = 365 and 375 nm. Measurements were performed at the temperature range of (120 ~ 220 K) and (110 ~ 230 K) for ZnGa 2 Se 4 and ZnGa 2 Se 4 :Eu 2+ , respectively. No PL was observed for both crystals at the temperatures higher than 220 K (ZnGa 2 Se 4 ) and 230 K (ZnGa 2 Se 4 :Eu 2+ ). At temperatures lower than ~220 K and ~230 K one and three lines were observed for ZnGa 2 Se 4 and ZnGa 2 Se 4 : Eu at 591 nm and 566, 591, 646 nm, respectively. 566 nm line was assigned as due of the 4f 6 5d→ 4f 7 ( 8 S 7/2 ) transition of Eu 2+ ions, whereas the rest two lines were attributed to the donor-acceptor recombination pairs. Probability of non-radiation transfers (A = 10 8 ~10 9 s -1 ), energy of optical phonons (hω= 25 ~ 30 meV), Huan Rice parameter (S = 8 ~ 10), energy of thermal quenching (△E = 0.02 ~ 0.06 eV) were determined from the tem-perature dependences of the full width at half maximum (FWHM = Г(T)).