Mid-infrared modulated photoluminescence mapping to investigate in-plane distributions of bandedge transitions in As-doped HgCdTe
Mid-infrared modulated photoluminescence mapping to investigate in-plane distributions of bandedge transitions in As-doped HgCdTe
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DOI：
10.1063/5.0164195
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发表时间：
2023-10
影响因子：
4
通讯作者：
Xiren Chen;Man Wang;Liang Zhu;Hao Xie;Lu Chen;Jun Shao
中科院分区：
文献类型：
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作者：
Xiren Chen;Man Wang;Liang Zhu;Hao Xie;Lu Chen;Jun Shao
窄间隙砷掺杂HgCdTe带边电子结构的面内分布是中红外探测器阵列研究的一个重要的基础和技术问题，但长期以来一直难以进行实验研究。这项工作报告了在砷掺杂的HgCdTe上进行调制光致发光（PL）映射的演示，其空间分辨率为典型的阵列像素尺度，并区分了精细的带边缘跃迁。与带隙和汞空位（VHg）、砷给体（AsHg）和AsHg - VHg对的杂质相关的曲线拟合在温度相关的PL分析的辅助下得到了证实。导出了Cd组成的空间非均匀性和杂质相对浓度的分布。相关分析表明，As原子直接取代完整晶格中的Hg原子和As原子占据已经存在的VHg是As掺杂过程中形成AsHg的两种途径。不均匀的带边特性会导致面内电导率波动，不利于阵列的性能。结果表明，探测砷掺杂HgCdTe的带边杂质均匀性对阵列制作具有重要意义，而调制PL映射是一种理想而有效的工具。
In-plane distribution of band edge electronic structure of the narrow-gap arsenic (As)-doped HgCdTe is a crucial topic fundamentally and technically for mid-infrared detector array but hard to be investigated for long experimentally. This work reports a demonstration of the modulated photoluminescence (PL) mapping carried on As-doped HgCdTe, with the spatial resolution of a typical array pixel scale and with the elaborate band edge transitions being distinguished. Curve fittings related to the bandgap and to the impurities of Hg vacancy (VHg), As donor (AsHg), and AsHg–VHg pair are confirmed for PL mapping assisted by a temperature-dependent PL analysis. The spatial non-uniformity of Cd composition and the distributions of impurity relative concentrations are derived. Correlation analysis suggests that the As atom directly replacing the Hg atom in the complete lattice and the As atom occupying the already-existing VHg are the two approaches for the AsHg formation during As doping. The non-uniform band edge properties may lead to the in-plane conductivity fluctuation detrimental to the array performance. The results indicate the significance of probing the band edge impurity uniformity of As-doped HgCdTe for arrays fabrication, and the modulated PL mapping serving as a desirable and effective tool.