Simulation of doping levels and deep levels in InGaN-based single-junction solar cell
Simulation of doping levels and deep levels in InGaN-based single-junction solar cell
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InGaN基单结太阳能电池的掺杂水平和深能级模拟
DOI：
10.1007/s10853-012-6321-6
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发表时间：
2012-06-01
影响因子：
4.5
通讯作者：
Zhang, Baoping
中科院分区：
文献类型：
--
作者：
Lin, Shuo;Zeng, Shengwei;Zhang, Baoping
对In_（0.65）Ga_（0.35）N单结太阳电池的掺杂能级和深能级进行了理论研究，并对电池特性进行了模拟。采用连续质量近似（EMA）计算了纤锌矿In_（0.65）Ga_（0.35）N中施主和受主的电离能和基态轨道半径。施主和受主的电离能分别估计为15.5和92.9 meV。讨论了电子探针对纤锌矿型InGaN合金的有效性。利用AMPS-1D软件模拟了In 0.65Ga 0.35N单结太阳电池的掺杂能级和深能级，并假设深能级位于In 0.65Ga 0.35N带隙的中间，此时复合最大。得到了平衡载流子的能带结构和浓度分布。当复合中心浓度为5 × 1015 cm-3，俘获截面为10 - 13 cm-2时，深能级复合对效率的影响约为9.6%。仿真结果表明，反向饱和电流的增大、开路电压（Voc）和填充因子（FF）的减小是导致效率下降的主要原因。短路电流密度（JSC）被发现是不敏感的深能级浓度和捕获截面。由于InGaN的晶体质量和富In InGaN的p型掺杂可能是InGaN太阳能电池面临的最重要的挑战，因此本研究对InGaN基超高效率太阳能电池的研究具有参考价值。
Doping levels and deep levels in In0.65Ga0.35N single junction solar cells are studied theoretically, and simulation of cell properties is performed. Effective-mass approximation (EMA) is used to calculate the ionization energies and the radius of ground-state orbit for donors and acceptors in wurtzite In0.65Ga0.35N. The ionization energies of donors and acceptors are estimated to be about 15.5 and 92.9 meV, respectively. The validity of EMA to wurtzite InGaN alloy has also been discussed. AMPS-1D software is used to simulate the doping levels and deep levels in In0.65Ga0.35N single junction solar cells with assumption that the deep level is located at the middle of In0.65Ga0.35N band gap where the recombination is maximum. Band structure and concentration distributions of equilibrium carriers are obtained. The influence of deep level recombination on efficiency is estimated to be about 9.6% while recombination center concentration is 5 × 1015cm−3, and capture cross section is 10−13cm2. The simulated results show that the increase of reverse saturation current and the decrease of open-circuit voltages (Voc) and fill factor (FF) are mainly responsible for the decrease of the efficiency. Short-circuit current density (Jsc) is found to be not sensitive to deep level concentrations and capture cross sections. As the crystal quality of InGaN and p-type doping of In-rich InGaN may be the most important challenges for InGaN solar cells, this study is useful for the study of InGaN-based super-high efficiency solar cells.