Impact of doping on InAs/GaAs quantum-dot solar cells: A numerical study on photovoltaic and photoluminescence behavior
Impact of doping on InAs/GaAs quantum-dot solar cells: A numerical study on photovoltaic and photoluminescence behavior
复制标题
DOI：
10.1016/j.solmat.2016.05.049
复制
发表时间：
2016-12
影响因子：
6.9
通讯作者：
F. Cappelluti;M. Gioannini;Arastoo Khalili
中科院分区：
文献类型：
--
作者：
F. Cappelluti;M. Gioannini;Arastoo Khalili
我们研究了掺杂对量子点（QD）太阳能电池的光伏特性，外量子效率，和室温下的光致发光（PL）方面的行为进行了分析。该分析解决了两种最普遍的QD选择性掺杂方法，即调制和直接掺杂，以获得掺杂分布和密度对太阳能电池行为的影响的全面器件级评估。使用基于物理的模型，准确地描述量子点载流子动力学的半经典漂移扩散泊松模型内的设备进行模拟。考虑了晶体质量方面的不同情况：在高质量材料中，接近辐射极限，预测大的开路电压恢复，这是由于通过QD基态的辐射复合的抑制。在有缺陷的材料中，由于非辐射和量子点基态辐射复合的抑制，也实现了显着的光伏恢复。在这两种情况下，PL发射从扩展的润湿层状态成为主导在高掺杂密度。详细分析了非辐射和量子点辐射复合通道之间的相互作用，以及它们之间的相互作用如何通过掺杂来改变。非故意的背景掺杂的interdot层和显着的非线性行为的开路PL相对于激发强度的细胞行为的强烈影响被证明。由此产生的图片提供了新的见解文献中的实验结果。
We investigate the effect of doping on quantum dot (QD) solar cells by analysing their behavior in terms of photovoltaic characteristic, external quantum efficiency, and photoluminescence (PL) at room temperature. The analysis addresses the two most widespread methods for QD selective doping, namely modulation and direct doping, to gain a comprehensive device-level assessment of the impact of doping profile and density on the solar cell behavior. Devices are simulated using a physics-based model that accurately describes QD carrier dynamics within a semi-classical drift-diffusion-Poisson model. Different scenarios in terms of crystal quality are considered: in the high-quality material, close to radiative limit, large open circuit voltage recovery is predicted, due to the suppression of radiative recombination through QD ground state. In the defective material, significant photovoltage recovery is also attained owing to the suppression of both nonradiative and QD ground state radiative recombination. In both cases, PL emission from extended wetting layer states becomes dominant at high doping density. The interplay between nonradiative and QD radiative recombination channels, and how their interaction is modified by doping, are analyzed in detail. Strong influence on the cell behavior of unintentional background doping of interdot layers and markedly nonlinear behavior of open circuit PL with respect to excitation intensity are demonstrated. The resulting picture provides new insight on the experimental results in literature.