EXCITED STATES OF 3d-ELECTRON AND LATTICE RELAXATION IN SEMIMAGNETIC-SEMICONDUCTORS

在低温下观察到Mn~(2+)~(2+)&GT~(2+)光致发光峰的能量随激发能的变化。利用这个位移，我们分别估计了Mn~(2+)和Gt~(2+)光致发光的非均匀展宽和均匀展宽。随着温度的升高，非均匀展宽的性质变为均匀展宽。研究了红外光致发光的时间分布，并用扩展态到局域态的能量传递解释了红外光致发光的建立过程。研究了2K下Mn~(2+)&lt；~(2+)&Gt~(2+)d-多重态激发态的高密度效应，并在高密度激发下观察到非指数衰减。在衰变曲线的初始部分，出现了寿命较短的额外衰变，其强度增大。这种效应被认为是超荧光或超辐射的前驱效应。

The energy shift of the Mn^<2+> photoluminescence peak according to excitation energy is observed at low temperatures. Using this shift we estimate inhomogeneou and homogeneous broadening of Mn^<2+> photoluminescence separately. In creasing temperatures inhomogeneous broadening changes its character to homogeneous one. Time profiles of infrared photoluminescence are investigated and their built up processes are explained using energy transfer from the extended states to localized states. High density effects of excited d-multiplet states of Mn^<2+> are investigated at 2K and nonexponential decay are observed at high density excitation. At the initial part of the decay profiles extra decay with short life time appear and its intensity increases. This effect is considered as the precursor effect of super flourescence or super radiance.