570 mV photovoltage, stabilized n-Si/CoOx heterojunction photoanodes fabricated using atomic layer deposition
570 mV photovoltage, stabilized n-Si/CoOx heterojunction photoanodes fabricated using atomic layer deposition
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DOI：
10.1039/c5ee03655k
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发表时间：
2016-03
影响因子：
32.5
通讯作者：
Xinghao Zhou;Rui Liu;K. Sun;Kimberly M. Papadantonakis;B. Brunschwig;N. Lewis
中科院分区：
文献类型：
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作者：
Xinghao Zhou;Rui Liu;K. Sun;Kimberly M. Papadantonakis;B. Brunschwig;N. Lewis
异质结光阳极由n型晶体Si（100）衬底组成，衬底上涂有一层用原子层沉积（ALD）方法制备的厚度约为50 nm的氧化钴薄膜，其光电流起始电位相对于析氧反应（OER）的形式电位为−205 ± 20 mV，理想的再生太阳能-O_2（g）转换效率为1.42 ± 0.20%，并在1.0M KOH（aq）中在模拟太阳光照下连续操作超过100天（约2500 h）。ALD CoO_x薄膜：（i）与n-Si（100）形成异质结，其在1太阳的模拟太阳光照下提供575 mV的光电压;和（iii）催化水的氧化，从而降低反应所需的动力学过电位并相对于不具有固有的过电位的电极增加总效率电催化涂层该工艺提供了一种简单有效的方法，用于使平面n-Si（100）衬底能够在完全集成的、光致发光偏置的太阳能燃料发电机中用作高效且耐用的光阳极。
Heterojunction photoanodes, consisting of n-type crystalline Si(100) substrates coated with a thin ∼50 nm film of cobalt oxide fabricated using atomic-layer deposition (ALD), exhibited photocurrent-onset potentials of −205 ± 20 mV relative to the formal potential for the oxygen-evolution reaction (OER), ideal regenerative solar-to-O_2(g) conversion efficiencies of 1.42 ± 0.20%, and operated continuously for over 100 days (∼2500 h) in 1.0 M KOH(aq) under simulated solar illumination. The ALD CoO_x thin film: (i) formed a heterojunction with the n-Si(100) that provided a photovoltage of 575 mV under 1 Sun of simulated solar illumination; (ii) stabilized Si photoanodes that are otherwise unstable when operated in aqueous alkaline electrolytes; and, (iii) catalyzed the oxidation of water, thereby reducing the kinetic overpotential required for the reaction and increasing the overall efficiency relative to electrodes that do not have an inherently electrocatalytic coating. The process provides a simple, effective method for enabling the use of planar n-Si(100) substrates as efficient and durable photoanodes in fully integrated, photovoltaic-biased solar fuels generators.