Modern metal-semiconductor-metal nano- and micro-structures exhibit unique properties related to both light emission and detection. Here we develop a novel optimized numerical model to calculate charge carrier density inside a n-type semiconductor micro-crystal that is sandwiched between two Schottky contacts. We use drift-diffusion equations and finite difference methods and utilize the Scharfetter-Gummel discretization technique. We demonstrate that the concentration of majority charge carriers in the semiconductor can be reduced below the level observed at zero applied bias by surpassing the current density of minority charge carriers beyond that of the majority charge carriers. Subsequently, minority charge carrier concentration increases and becomes the dominant charge carrier inside the semiconductor at high applied bias. In addition, we provide evidence that the open circuit voltage of a semiconductor under illumination occurs at the point where the minority-majority current densities intersect. By adjusting the Schottky contact barrier, the crossing potential between minority and majority carriers can be controlled, thereby allowing for manipulation of the open circuit voltage. This is an important factor in determining the density of trap states in the semiconductor and designing an open circuit voltage photodetector. We verify our results using COMSOL Multiphysics software and show that our numerical approach is found to be more time-efficient than the methods employed by COMSOL Multiphysics.

中文翻译：

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基于金属-半导体-金属结构的光发射器或检测器装置中电荷载流子注入的数值分析

现代金属-半导体-金属纳米和微米结构表现出与光发射和检测相关的独特特性。在这里，我们开发了一种新颖的优化数值模型来计算夹在两个肖特基接触之间的 n 型半导体微晶体内的电荷载流子密度。我们使用漂移扩散方程和有限差分方法，并利用 Scharfetter-Gummel 离散化技术。我们证明，通过超过少数电荷载流子的电流密度，可以将半导体中多数电荷载流子的浓度降低到零施加偏压时观察到的水平以下。随后，少数载流子浓度增加，并在高偏压下成为半导体内部的主要载流子。此外，我们提供的证据表明，照明下半导体的开路电压发生在少数与多数电流密度相交的点。通过调整肖特基接触势垒，可以控制少数载流子和多数载流子之间的交叉电势，从而可以控制开路电压。这是确定半导体中陷阱态密度和设计开路电压光电探测器的重要因素。我们使用 COMSOL Multiphysics 软件验证了我们的结果，并表明我们的数值方法比 COMSOL Multiphysics 采用的方法更省时。