摘要
用两步退火法在掺 Cd Se S的玻璃中制备了高密度的量子点 ,均匀性较好 .量子点尺寸随第二步退火时间加长而增大 ,但组份基本不变 .研究了量子点光学性质与退火时间的依赖关系 ,证明光致发光谱中的低能峰与量子点表面缺陷态有关 .量子点尺寸越小 ,比表面积越大 。
High density quantum dots (QD) are pr epared by using heat treatment of CdSeS alloy-doped glass in a two-step anneal ing process.The size of QDs increases with the annealing time in the second step ,while their composition is nearly unchanged.The lineshape of photoluminescence (PL) excitation spectra varies with the detection photon energy,mainly due to th e size distribution of the microcrystallites.The strong PL peak at the lower ene rgy side of the excitonic peak of QDs can be excited only by the intrinsic excit ation,indicating that it is induced by the defect states of QDs,es pecially those on the surface of microcrystallites.
基金
国家自然科学基金资助项目 (批准号 :2 9890 2 17和 698760 3 7)
