GaInAs/AlInAs多量子阱结构光学性质的研究

我们研究了与InP衬底晶格匹配的GaInAs/AlInAs三元材料多量子阱异质结构的光学性质,测量了不同阱宽量子阱在低温下的吸收光谱、光致发光及其激发光谱,以及吸收光谱随温度的变化.所测样品的光致发光峰主要取决于与缺陷态有关的跃迁过程,但吸收光谱中直到室温仍观察到重轻空穴的本征激子峰.吸收光谱线形明显地反映了多量子阱中电子态的二维特性.对不同量子阱中各子带间跃迁能量因温度上升而产生的红移进行了测定和分析.用Kronig-Penney模型对子带能量所作的计算表明,为了与测量到的跃迁能量获得满意的拟合,必须在计算中计入导带和价带的非抛物线性效应.我们结合光学性质和X光双晶衍射测量,对层厚、应变和组份均匀性等样品结构参量进行了分析.

Investigations on Optical Properties of GaInAs/AlInAs Multiple Quantum Well Heterostructures

The optical properties of GaInAs/AllnAs all-ternary multiple quantum well heterostru-ctures (MQWH), lattice-matched to InP substrate,are investigated.The low temperature abso-rption,photoluminescence (PL), PL excitation spectra and the temperature dependence oftransmission spectra are measured for the MQWH samples with different well widths.Thedetected PL peaks from MQWH samples are mainly due to transition processes related to de-fect states. However, up to room temperature the intrinsic heavy-and light-hole exciton peaksare still well observed in the absorption spectra, showing clearly the two-dimensional characterOf the electronic states. The red shift of inter-subband transition energies with increasing tem-perature is determined and explained. The calculation of subband energies by Kronig-Penneymodel indicates that, in order to get a satisfactory fitting to the measured values it is nessesaryto take the non-parabolicity of conduction and valence bands into account. In connectionwith X-ray double crystal diffraction measurements,structural parameters as layer thiskness,residual strains and the composition homogeneities are analysed.