Lahreche Abderrezak, Babichev Andrey V, Beggah Yamina, Tchernycheva Maria
Department de technologie, Université A.Mira de Bejaia, 6000 Bejaia, Algérie.
Laboratoire Matériaux: Elaborations-Propriétés - Applications (LMEPA), Université Jijel, 18000 Jijel, Algérie.
Nanotechnology. 2022 Jul 4;33(39). doi: 10.1088/1361-6528/ac7887.
A tridimensional mathematical model to calculate the electron beam induced current (EBIC) of an axial p-n nanowire junction is proposed. The effect of the electron beam and junction parameters on the distribution of charge carriers and on the collected EBIC current is reported. We demonstrate that the diffusion of charge carriers within the wire is strongly influenced by the electrical state of its lateral surface which is characterized by a parameter called surface recombination velocity (). When the surface recombination is weak (i.e. lowvalue), the diffusion of charge carriers occurs in one dimension (1D) along the wire axis, and, in this case, the use of bulk EBIC models to extract the diffusion length () of charge carriers is justified. However, when the surface effects are strong (i.e. highvalues), the diffusion happens in three dimensions (3D). In this case, the EBIC profiles depend onvalue and two distinct cases can be defined. If theis larger than the nanowire radius (), the EBIC profiles show a strong dependency with this parameter. This gives evidence that the recombination of generated carriers on the surface throughis the dominant process. In this situation, a decrease of two orders of magnitude in the EBIC profiles computed with a high and a lowvalue is observed in neutral regions of the junction. For the case ofsmaller thanthe dependency of the EBIC profiles on theis weak, and the prevalent recombination mechanism is the bulk recombination process.
提出了一种用于计算轴向 p-n 纳米线结的电子束感应电流（EBIC）的三维数学模型。报告了电子束和结参数对电荷载流子分布以及收集到的 EBIC 电流的影响。我们证明，纳米线内电荷载流子的扩散受到其侧面电状态的强烈影响，该侧面电状态由一个称为表面复合速度（）的参数表征。当表面复合较弱（即低值）时，电荷载流子沿纳米线轴在一维（1D）中扩散，在这种情况下，使用体 EBIC 模型来提取电荷载流子的扩散长度（）是合理的。然而，当表面效应较强（即高值）时，扩散发生在三维（3D）中。在这种情况下，EBIC 分布取决于值，并且可以定义两种不同的情况。如果大于纳米线半径（），EBIC 分布显示出与该参数的强烈相关性。这表明通过在表面上产生的载流子的复合是主要过程。在这种情况下，在结的中性区域中，观察到用高值和低值计算的 EBIC 分布下降了两个数量级。对于小于的情况，EBIC 分布对的依赖性较弱，并且普遍的复合机制是体复合过程。
