Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China SAR.
ACS Nano. 2013 Mar 26;7(3):2725-32. doi: 10.1021/nn400160n. Epub 2013 Feb 19.
Efficient light absorption in thin-film photovoltaic (PV) devices is crucial for improving their efficiency and reducing cost. Here we have not only developed a low-cost and scalable method to fabricate a unique type of integrated-nanopillar-nanowell (i-NPW) structure by integrating nanopillar and nanowell arrays together vertically, but also demonstrated the attractive optical property of the i-NPW arrays by leveraging the advantages of "positive" and "negative" nanostructures for photon harvesting. Impressively, the 2 μm thick i-NPW arrays with only 40 nm a-Si coating obtained a day-integrated absorption of 89.27%, as opposed to only 33.45% for the planar control sample. These results suggest the feasibility and clear advantage of vertical integration of three-dimensional (3-D) nanophotonic structures, and meanwhile also pave a viable and convenient way toward a 3-D ultrathin film PV module with potency for high energy conversion efficiency.
在薄膜光伏 (PV) 器件中实现高效的光吸收对于提高效率和降低成本至关重要。在这里，我们不仅开发了一种低成本且可扩展的方法，通过垂直集成纳米柱和纳米井阵列来制造独特的集成纳米柱-纳米井 (i-NPW) 结构，而且还通过利用“正”和“负”纳米结构的优势来展示 i-NPW 阵列的诱人光学特性，从而实现光子捕获。令人印象深刻的是，厚度为 2μm、仅涂有 40nm 的非晶硅的 i-NPW 阵列的日间总吸收率达到了 89.27%，而平面对照样品的吸收率仅为 33.45%。这些结果表明了三维 (3-D) 纳米光子结构垂直集成的可行性和明显优势，同时也为具有高效能量转换效率潜力的 3-D 超薄光伏模块开辟了一条可行且便捷的道路。
