Tin Oxide as a Protective Heterojunction with Silicon for Efficient Photoelectrochemical Water Oxidation in Strongly Acidic or Alkaline Electrolytes
Tin Oxide as a Protective Heterojunction with Silicon for Efficient Photoelectrochemical Water Oxidation in Strongly Acidic or Alkaline Electrolytes
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DOI：
10.1002/aenm.201801155
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发表时间：
2018-08-27
影响因子：
27.8
通讯作者：
Lewis, Nathan S.
中科院分区：
文献类型：
--
作者：
Moreno-Hernandez, Ivan A.;Brunschwig, Bruce S.;Lewis, Nathan S.
没有 p-n 结的光电极通常因半导体表面的电荷复合和向电催化剂的电荷转移缓慢而限制效率。这项研究报告称，在形成薄薄的化学氧化SiOx层后，将氧化锡（SnOx）层应用于n-Si晶片，可以钝化Si表面，同时在100 mW cm(-2)的模拟太阳光下产生大约620 mV的光电压。 SnOx 层与 Ni、Ir 或 Pt 薄膜形成欧姆接触，这些薄膜充当 1.0 m KOH(aq) 或 1.0 (M) H2SO4(aq) 中析氧反应 (OER) 的预催化剂。在含有 Ni 的 1.0 m KOH(aq) 或含有 Pt/IrOx 层的 1.0 m H2SO4(aq) 作为 OER 催化剂时，理想的太阳能转化为 O-2(g) 的再生效率分别为 4.1% 和 3.7%。具有图案化催化剂层的电极在 1.0 (M) KOH(aq) 和 1.0 m H2SO4(aq) 中均获得了 >100 小时的稳定光电流。
Photoelectrodes without a p-n junction are often limited in efficiency by charge recombination at semiconductor surfaces and slow charge transfer to electrocatalysts. This study reports that tin oxide (SnOx) layers applied to n-Si wafers after forming a thin chemically oxidized SiOx layer can passivate the Si surface while producing approximate to 620 mV photovoltage under 100 mW cm(-2) of simulated sunlight. The SnOx layer makes ohmic contacts to Ni, Ir, or Pt films that act as precatalysts for the oxygen-evolution reaction (OER) in 1.0 m KOH(aq) or 1.0 (M) H2SO4(aq). Ideal regenerative solar-to-O-2(g) efficiencies of 4.1% and 3.7%, respectively, are obtained in 1.0 m KOH(aq) with Ni or in 1.0 m H2SO4(aq) with Pt/IrOx layers as OER catalysts. Stable photocurrents for >100 h are obtained for electrodes with patterned catalyst layers in both 1.0 (M) KOH(aq) and 1.0 m H2SO4(aq).