PbSe films were grown on(111)-oriented BaF_(2)substrates by using molecular beam epitaxy.High resolution x-ray diffraction characterization showed good crystalline quality of PbSe films.Both longitudinal optical phono...PbSe films were grown on(111)-oriented BaF_(2)substrates by using molecular beam epitaxy.High resolution x-ray diffraction characterization showed good crystalline quality of PbSe films.Both longitudinal optical phonon at 135cm^(-1)and transverse optical phonon at 47.6cm-1 were observed by Raman scattering measurements.The Raman tensor calculation demonstrates that both transverse-optical and longitudinal-optical(LO)phonons in PbSe crystal are Raman active on(111)-oriented surface,Furthermore,2LO phonon at about 270cm^(-1)and polaron at about 800cm^(-1)in PbSe,were also observed.The observed Raman frequencies are in good agreement with theoretical calculations using point ion model.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grant No.69606006Oklahoma Center for the Advancement of Science and Technology(OCAST#AR6-054).
文摘PbSe films were grown on(111)-oriented BaF_(2)substrates by using molecular beam epitaxy.High resolution x-ray diffraction characterization showed good crystalline quality of PbSe films.Both longitudinal optical phonon at 135cm^(-1)and transverse optical phonon at 47.6cm-1 were observed by Raman scattering measurements.The Raman tensor calculation demonstrates that both transverse-optical and longitudinal-optical(LO)phonons in PbSe crystal are Raman active on(111)-oriented surface,Furthermore,2LO phonon at about 270cm^(-1)and polaron at about 800cm^(-1)in PbSe,were also observed.The observed Raman frequencies are in good agreement with theoretical calculations using point ion model.
