Crystallization of Amorphous GeSe2 Semiconductor by Isothermal Annealing without Light Radiation

Abstract

The thermal-induced crystallization process of melt-quenched amorphous GeSe2 was studied. The low-temperature (LT) form, LT-GeSe2 and the high-temperature (HT) form, HT-GeSe2 were observed with Raman spectroscopy, differential scanning calorimetry (DSC) and an X-ray diffractometer. We observed the X-ray diffraction pattern of LT-GeSe2 and identified the reflection index. The crystal parameters resembled those of LT-GeS2 crystal. The growth conditions for crystallization of LT-GeSe2 and HT-GeSe2 were clarified from the time-temperature-transformation diagram. It was found that amorphous GeSe2 crystallizes at first into LT-GeSe2 and then LT-GeSe2 changes into HT-GeSe2. The activation energy (E a)) from amorphous GeSe2 to LT-GeSe2 is estimated to be 4.6 eV from the DSC measurement which corresponds to the boundary of the phases in the T-T-T diagram. The activation energy from LT-GeSe2 to HT-GeSe2 could not be obtained.