分子束外延生长的InAs/GaAs自组织量子点发光特性

研究了分子束外延生长的覆盖了1nm的InxAl1-xAs(x=0.2,O.3)和3nm的Ino2Gao8As复合应力缓冲层InAs/GaAs自组织量子点(QD)光致发光(PL)特性.加InAlAs层后PL谱红移到1.33μm,室温下基态和第一激发态间的跃迁能级差增加到86meV.高In组份的InAlAs有利于获得较长波长和较窄的半高宽(FWHM).对于覆盖复合应力缓冲层的QD不会使波长和FWHM发生显著变化,但可以使基态和第一激发态间的能级差进一步增大.这些结果归因于InAlAs能够有效的抑制In的偏析,减少应力,使QD保持较高的高度.同时,由于InAlAs具有较高的限制势垒,可以增加基态和第一激发态间的能级差.     

新奇半导体低维结构的自组织生长

文章介绍了自组织生长半导体量子线、量子点和量子环的进展，同时介绍了这些低维半导体材料在光电子和通信等领域应用情况。此外，对这些材料的一些测试方法也进行了介绍．     

Photoluminescence of Self－Assembled InAs／GaAs Quantum Dots Covered by InAlAs and InGaAs Combination Strain－Reducing Layer

Self-assembled lnAs/GaAs quantum dots covered by the 1-nm InxAI(1-x)As (x = 0.2, 0.3) and 3-nm In0.2Ga0.8As combination strain-reducing layer are fabricated, whose height can take up to 30-46 nm. The luminescence emission at a long-wavelength of 1.33μm and the energy separation between the ground and the first-excited state of 86meV are observed at room temperature. Furthermore, comparative study proves that the energy separation can increase to 91 meV by multiple stacking.