Ge基Ⅲ-Ⅴ族半导体能源材料生长与性能研究

发布时间：2018-05-04 20:51

  本文选题：金属有机化学气相沉积 + 分子束外延　； 参考：《河北工业大学》2015年硕士论文

【摘要】：近些年来,半导体材料在太阳能发电系统的应用方面研究已经大幅成长。由于III-V族化合物多结太阳电池具有多能隙组合与直接能隙材料对光的高吸收率等优点受到了越来越多的关注。Ge基多结电池是太空用最具潜力的电池结构。本论文研究了Ge基电池中所使用的III-V族半导体材料生长与其性能,所得成果如下:(1)用MOVPE生长了带有AlAs超薄插入层的GaInP试样,并用高分辨透射电子显微镜(HRTEM)、光致发光谱(PL),拉曼光谱(Raman)和表面形貌测试等手段表征了它们的结构和光学性质。5?的Al As插入层导致了由[Ge(Ga,In)-V(Ga,In)]络合物引起的PL宽峰强度的减弱。加入AlAs插入层后,Ga InP的有序度得到了提高。当AlAs插入层的厚度由5?上升到5 nm时,为了降低界面应变能,有序度进一步得到提高。另一方面,在时间分辨光致发光谱中,我们观察到了双指数衰减曲线,其中的快过程对应有序态GaInP的带带跃迁,慢过程对应局域态的跃迁。随着AlAs层的加入和厚度的增加,GaInP有序度增加,PL的衰减寿命随之增加。(2)用全固态源MBE设备生长了GaAs/Ge和GaInP/Ge系列的样品,并通过透射电子显微镜(TEM),光致发光谱(PL),和拉曼光谱(Raman)对它们的结构和光学性质进行了表征。在含有较多反向畴的GaAs/Ge试样中(Ge03和Ge07),可以观察到一个位于1.75eV处的反常的PL发光峰。通过1 nm的GaAs缓冲层退火工艺,促进了界面处反向畴的自湮灭,从而基本消除了此反常的发光峰(Ge08)。在GaInP/Ge系列的样品中,通过对520℃(Ge25)和480℃(Ge26)两种不同温度下生长的样品的发光性质研究,我们发现生长温度越高,本征发光峰的强度越弱。由于生长温度较高时导致了组分分布不均,PL发光峰的峰位随着测试位置的变化发生了一定程度的偏移。退火后样品(Ge14)的PL峰位发生了一定程度的红移,此红移来源于退火后In组分的飘移。在低温下(TC=460-470℃)生长的Ga InP外延层,通过对其光学性质的研究,发现有序和无序态共存,材料中并不存在与缺陷能级有关的辐射复合发光中心。当温度升高时,载流子由于热激发更趋向于通过有序GaInP材料中的带尾态进行复合。
[Abstract]:In recent years, the application of semiconductor materials in solar power systems has grown dramatically. Due to the advantages of III-V family compound multijunction solar cells, such as multigap combination and high absorptivity of direct energy gap materials, more and more attention has been paid to the fact that the GE base multijunction solar cells are the most promising structures for space applications. In this paper, the growth and properties of III-V semiconductor materials used in GE based batteries are studied. The results obtained are as follows: (1) GaInP samples with AlAs ultrathin intercalation layer were grown by MOVPE. Their structures and optical properties were characterized by means of high resolution transmission electron microscopy (HRTEM), photoluminescence (PL), Raman spectroscopy (Raman) and surface morphology measurements. The Al as intercalation layer leads to the decrease of the PL peak intensity caused by the [Geo GaN In-VN] complex. The order degree of Ga InP was improved with the addition of AlAs insertion layer. When AlAs inserts the thickness of the layer from 5? In order to decrease the interfacial strain energy, the degree of order is further improved when the interfacial strain energy reaches 5 nm. On the other hand, in the time-resolved photoluminescence, we have observed the double exponential decay curve, in which the fast process corresponds to the band transition of ordered GaInP, and the slow process corresponds to the transition of local state. With the addition of the AlAs layer and the increase of the thickness, the decay life of the PL increases with the increase of the ordering degree of GaInP.) the samples of GaAs/Ge and GaInP/Ge series have been grown by all-solid-state MBE equipment. Their structures and optical properties were characterized by transmission electron microscopy (TEM), photoluminescence (PL) and Raman spectroscopy (Raman). In GaAs/Ge samples containing more reverse domains, a anomalous PL emission peak at 1.75eV can be observed. By annealing at 1 nm of GaAs buffer layer, the self-annihilation of the reverse domain at the interface is promoted, and the anomalous luminescence peak Ge08N is basically eliminated. In the GaInP/Ge series samples, the luminescence properties of the samples grown at 520 鈩，

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