GaAs/InGaP Core–Multishell Nanowire-Array-Based Solar Cells
GaAs/InGaP Core–Multishell Nanowire-Array-Based Solar Cells
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DOI：
10.7567/jjap.52.055002
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发表时间：
2013-05
影响因子：
1.5
通讯作者：
E. Nakai;M. Yoshimura;K. Tomioka;T. Fukui
中科院分区：
文献类型：
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作者：
E. Nakai;M. Yoshimura;K. Tomioka;T. Fukui
半导体纳米线（NW）是下一代光伏材料中光吸收材料的良好候选者，并且使用晶格失配材料系统的基于III-V NW的多异质结太阳能电池被期望为在集中光下的高能量转换效率。在这里，我们展示了核-壳GaAs NW阵列，通过使用无催化剂的选择性区域金属有机气相外延（SA-MOVPE）作为多结太阳能电池的基础。没有任何抗反射涂层的NW阵列的反射率比平面晶片的反射率低得多。接下来，我们制作了具有径向p-n结的核-壳GaAs NW阵列太阳电池。尽管反射率低，能量转换效率为0.71%，因为光生载流子的高表面复合率和GaAs和透明氧化铟锡（ITO）电极之间的欧姆接触差。为了避免这些退化，我们引入了InGaP层和Ti/ITO电极。其结果是，我们得到了12.7 mA cm-2的短路电流，0.5 V的开路电压，和0.65的填充因子为4.01%的总效率。
Semiconductor nanowires (NWs) are good candidate for light-absorbing material in next generation photovoltaic and III–V NW-based multi-heterojunction solar cells using lattice-mismatched material system are expected as high energy-conversion efficiencies under concentrated light. Here we demonstrate core–shell GaAs NW arrays by using catalyst-free selective-area metal organic vapor phase epitaxy (SA-MOVPE) as a basis for multijunction solar cells. The reflectance of the NW array without any anti-reflection coating showed much lower reflection than that of a planar wafer. Next we then fabricated core–shell GaAs NW array solar cells with radial p–n junction. Despite the low reflectance, the energy-conversion efficiency was 0.71% since a high surface recombination rate of photo-generated carriers and poor ohmic contact between the GaAs and transparent indium–tin-oxide (ITO) electrode. To avoid these degradations, we introduced an InGaP layer and a Ti/ITO electrode. As a result, we obtained a short-circuit current of 12.7 mA cm-2, an open-circuit voltage of 0.5 V, and a fill factor of 0.65 for an overall efficiency of 4.01%.