CAJ | 학술논문

研究了暴露在空气中退火和表面覆盖蓝宝石基板退火对MOCVD生长的ZnO薄膜光学性质的影响.研究发现,暴露在空气中退火虽可以去除薄膜中的氢杂质,并在低温光致发光(PL)谱中观察到与氢相关的束缚激子峰消失,但是退火后样品室温PL谱中可观察到很强的可见光发射,表明样品中引入了大量的深能级,样品的自由激子发光没有增强.而表面覆盖蓝宝石基板退火的样品,有效去除了氢杂质,但没有观察到可见光发射,说明表面覆盖蓝宝石基板退火可以有效地保护ZnO表面不分解,不生成深能级中心.由于激子束缚中心的减少,表面覆盖退火样品的自由激子发射大大增强.
연구료폭로재공기중퇴화화표면복개람보석기판퇴화대MOCVD생장적ZnO박막광학성질적영향.연구발현,폭로재공기중퇴화수가이거제박막중적경잡질,병재저온광치발광(PL)보중관찰도여경상관적속박격자봉소실,단시퇴화후양품실온PL보중가관찰도흔강적가견광발사,표명양품중인입료대량적심능급,양품적자유격자발광몰유증강.이표면복개람보석기판퇴화적양품,유효거제료경잡질,단몰유관찰도가견광발사,설명표면복개람보석기판퇴화가이유효지보호ZnO표면불분해,불생성심능급중심.유우격자속박중심적감소,표면복개퇴화양품적자유격자발사대대증강.
ZnO films grown by metal organic chemical vapor deposition at atmospheric pressure are annealed at850℃, with the film surfaces exposed to air or covered by a sapphire wafer. The optical properties of the as-grown and the annealed samples are studied by photoluminescence (PL) spectroscopy. It is found that the air-exposure annealing effectively removes the hydrogen impurities from the ZnO films but greatly increases the deep-level emission. In the surface-covered annealed sample, an elimination of the hydrogen impurities is also observed, and the deep-level emission disappears completely. The free exciton emission is significantly enhanced in the ZnO film after surface-covered annealing.