窄阱ZnSe—ZnS应变多量子阱的制备和鉴定

本文报导了利用常压MOCVD法制备窄阱ZnSe•ZnS应变多量子阱的方法,经X射线衍射、光致发光(PL)及扫描电镜(SEM)实验测定表明,该结构具有较好的结晶质量,阱宽约为0.5nm。

PREPARATION AND APPRAISAL OF NARROW WELL ZnSe-ZnS STRAINED-LAYER QUANTUM WELL

ZnSe is a direct-gap Semiconductor with the zinc-blende crystal structure and a relatively large band-gap energy of 2.7eV at 300K. Excitons in ZnSe are strongly bound with a binding energy of ~20meV. Recently, attention has been paid to the strained layer quantum well using a ZnSe layer as the well material, which provides the possibility to obtain excitonic emission and optical bistability (OB).The growth of ZnSe-ZnS MQWs with steep interface and narrow well have an important significance for studying quantum size effect, subband transition and carrier scattering. Taike et al.2] has reported the growth of ZnSe-ZnS SLS with well thickness (Lw) of ~0.5nm by MBE. But the PL peak position is about 430nm which is not agreed with the result calculated by Kroning-Penney model. In this paper, we report, for the first time, the preparation of narrow well ZnSe-ZnS MQWs with well Thickness(Lw) of ~0.5nm and the excitonic peak blue shift to 375nm (3.304eV). X-ray diffraction shows the ZnSe-ZnS with good quality periodic structure. The excitonic peak in PL spectrum shifts towards higher energy side as the well thickness reducing, indicating the quantum size effect of the ZnSe-ZnS MQWs.