Energy-Conversion Properties of Vapor-Liquid-Solid-Grown Silicon Wire-Array Photocathodes
Energy-Conversion Properties of Vapor-Liquid-Solid-Grown Silicon Wire-Array Photocathodes
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DOI：
10.1126/science.1180783
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发表时间：
2010-01-08
期刊：
影响因子：
56.9
通讯作者：
Lewis, Nathan S.
中科院分区：
文献类型：
--
作者：
Boettcher, Shannon W.;Spurgeon, Joshua M.;Lewis, Nathan S.
硅线阵列，虽然有吸引力的材料，用于在光电子学和作为光电阴极的氢产生，迄今已表现出性能差。采用铜催化的气液固生长工艺，在p（+）-Si（111）衬底上用SiCl 4和BCl 3生长了有序的p型硅（p-Si）微晶线阵列。当这些线阵列被用作光电阴极接触的甲基紫精（2+/+）电解质水溶液中，高达3%的能量转换效率被观察到单色808纳米光通量太阳能照明，尽管在短路的外部量子产率只有0.2。内部量子产率至少为0.7，表明所测量的光电流受到线阵列中光吸收的限制，线阵列仅占我们测试设备中入射光学平面的4%。因此，这些线的固有性能在概念上允许开发基于径向结平台的高效光伏和光电化学能量转换装置。
Silicon wire arrays, though attractive materials for use in photovoltaics and as photocathodes for hydrogen generation, have to date exhibited poor performance. Using a copper-catalyzed, vapor-liquid-solid-growth process, SiCl4 and BCl3 were used to grow ordered arrays of crystalline p-type silicon (p-Si) microwires on p(+)-Si(111) substrates. When these wire arrays were used as photocathodes in contact with an aqueous methyl viologen(2+/+) electrolyte, energy-conversion efficiencies of up to 3% were observed for monochromatic 808-nanometer light at fluxes comparable to solar illumination, despite an external quantum yield at short circuit of only 0.2. Internal quantum yields were at least 0.7, demonstrating that the measured photocurrents were limited by light absorption in the wire arrays, which filled only 4% of the incident optical plane in our test devices. The inherent performance of these wires thus conceptually allows the development of efficient photovoltaic and photoelectrochemical energy-conversion devices based on a radial junction platform.