Optically injected electron gas and formation of charged excitons in type-II ZnSe/BeTe quantum wells
Optically injected electron gas and formation of charged excitons in type-II ZnSe/BeTe quantum wells
复制标题
DOI：
10.1088/1742-6596/51/1/092
复制
发表时间：
2006-11
期刊：
影响因子：
--
通讯作者：
H. Mino;Z. Ji;A. Kano;K. Oto;K. Muro;R. Akimoto;S. Takeyama
中科院分区：
文献类型：
--
作者：
H. Mino;Z. Ji;A. Kano;K. Oto;K. Muro;R. Akimoto;S. Takeyama
利用泵浦探测方法研究了ZnSe/BeTe Ⅱ型量子阱结构中光生电子的积累效应。使用连续波半导体激光器作为泵浦光源。随着泵浦强度的增加，中性激子（X）的吸收减弱，并且在ZnSe QW层中的X的6 meV低能侧观察到由于带负电荷的激子（X-）引起的明显的峰结构。X−的圆极化的磁场依赖性包含了关于二维电子气（2DEG）密度的信息。我们发现，通过成功使用没有n掺杂层的II型量子结构，可以光学注入高密度2DEG（~1× 1011 cm-2）。
We have investigated the effect of accumulation of photo-created electrons in ZnSe/BeTe type-II quantum well (QW) structures by means of a pump-and-probe method in high magnetic field up to 7 T. A cw-diode laser was used as a pumping light source. With increasing pumping intensity neutral exciton (X) absorption are weakened and a distinct peak structure due to negatively charged exciton (X−) was observed at a 6 meV lower energy side of the X in ZnSe QW layers. The magnetic field dependence of circular polarization of X− contains information about the density of twodimensional electron gas (2DEG). We found that high-density 2DEG (~1×1011cm−2) is optically injected by successfully using type-II quantum structures without n-doped layers.