CdZnTe晶片显微光致发光谱中的等效温度分布研究

提出并实现了用微米级空间分辨率的显微光致发光（μ-PL)平面扫描谱对CdZnTe(CZT)晶片的表面亚微米层特性研究。在含缺陷区域进行微米尺度和在大面积范围内进行毫米尺度的逐点PL测量。对测得每一点的PL谱进行了拟合。拟合参数中等效温度Tc的统计分布给出两个分布中心，表明存在有两种机制的发光过程。同时统计结果给出发光各点的不均匀性。等效温度的平面分布图直观地给出了各温度的平面位置，样品经溴 抛光后重复类似的测量，结果表明等效湿度的统计均匀性大为改善。抛光后的不同的缺陷点表现出不同的发光特性，意味着各自起源的不同。大面积PL扫描的统计结果和平面分布给出样品特性的整体评价。

DISTRIBUTION OF EFFECTIVE TEMPERATURE IN MICRO-PHOTOLUMINESCENCE MAPPING ON CdZnTe WAFER

Micro-photoluminescence (μ-PL) mapping with the spatial resolution of micrometer was performed on a CdZnTe(CZT) wafer to study its characteristics of the sub-micrometer layer under the surface. Two scales of mapping on micrometer over the defect-containing region and on millimeter over the large area were employed. Each acquired PL spectrum was fitted based on a physical model. Statistical results of the fitting parameters of effective temperature Te show two centers for the temperature distribution, implying two mechanisms for the PL processes. The inhomogeneity for the luminescent points was also shown by the statistics. The maps of Te directly give the temperature position of each PL points. Similar μ-PL mapping was carried out after Br polishing on the sample surface. The fitting results show a good improvement on the homogeneity of Te. The two different defects on the Te map after polishing show different behavior, suggesting different origins for them. The statistics and the map of Te in μ-PL mapping on the scale of millimeter over large area demonstrate the general properties of the CZT wafer.