Modelling of Kelvin probe surface voltage and photovoltage in dielectric-semiconductor interfaces
Modelling of Kelvin probe surface voltage and photovoltage in dielectric-semiconductor interfaces
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DOI：
10.1088/2053-1591/ac84c8
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发表时间：
2022-08-01
影响因子：
2.3
通讯作者：
Bonilla, Ruy Sebastian
中科院分区：
文献类型：
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作者：
Bonilla, Ruy Sebastian
利用开尔文探头表面电压和光电压表征介电-半导体界面已成为提取影响光电子器件电学特性的一种广泛方法。开尔文探头提供了一种多功能、非接触式、无真空的技术，能够提供对半导体表面电子结构的有用见解。半导体理论长期以来一直被用来解释从表面电压测量中观察到的现象，通常是通过对系统特性做出大的假设来解释的。在这项工作中，我报告了一种最新的理论处理方法，用于模拟开尔文探测器表面电压和光电压的测量结果，包括四个关键机制：存储在界面表面态的电荷浓度，存储在表面介质薄膜不同位置的电荷，由于电荷重新分布而导致的有效寿命和过剩载流子密度的变化，以及在用于光电子器件钝化和光学改进的大多数大规模薄膜涂层上观察到的电荷不均匀。绘制了一个完整的模型并进行了解析求解，以举例说明这些机制在表面电压表征中所起的作用。这项工作中的处理提供了对半导体中产生表面电势的机制的关键理解。因此，这项工作将有助于设计和开发更好的光电子器件。
The characterisation of dielectric-semiconductor interfaces via Kelvin probe surface voltage and photovoltage has become a widespread method of extracting the electrical properties influencing optoelectronic devices. Kelvin probe offers a versatile, contactless and vacuum-less technique able to provide useful insights into the electronic structure of semiconductor surfaces. Semiconductor theory has long been used to explain the observations from surface voltage measurements, often by making large assumptions about the characteristics of the system. In this work I report an updated theoretical treatment to model the results of Kelvin probe surface voltage and photovoltage measurements including four critical mechanisms: the concentration of charge stored in interface surface states, the charge stored in different locations of a surface dielectric thin film, the changes to effective lifetime and excess carrier density as a result of charge redistribution, and the non-uniformity of charge observed on most large scale thin film coatings used for passivation and optical improvement in optoelectronic devices. A full model is drawn and solved analytically to exemplify the role that these mechanisms have in surface voltage characterisation. The treatment in this work provides crucial understanding of the mechanisms that give rise to surface potential in semiconductors. As such this work will help the design and development of better optoelectronic devices.