초록 |
A stoichiometric mixture of evaporating materials for AgGaS2 single crystal thin films was prepared from horizontal electric furnace. To obtain the single crystal thin films, AgGaS2 mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (HWE) system. The source and substrate temperatures were 590 ℃ and 440 ℃, respectively. The temperature dependence of the energy band gap of theAgGaS2 obtained from the absorption spectra was well described by the Varshni's relation, Eg(T) = 2.7284 eV - (8.695 × 10-4 eV/K)T2/(T + 332 K). After the as-grown AgGaS2 single crystal thin films was annealed in Ag-, S-, and Ga-atmospheres, the origin of point defects of AgGaS2 single crystal thin films has been investigated by the photoluminescence(PL) at 10 K. |