Department of Photonics, National Chiao-Tung University, Hsinchu, Taiwan, Republic of China.
Nanotechnology. 2011 Mar 4;22(9):095201. doi: 10.1088/0957-4484/22/9/095201. Epub 2011 Jan 24.
As silicon photovoltaics evolve towards thin-wafer technologies, efficient optical absorption for the near-infrared wavelengths has become particularly challenging. In this work, we present a solution that employs combined micro- and nano-scale surface textures to increase light harvesting in the near-infrared for crystalline silicon photovoltaics, and discuss the associated antireflection and scattering mechanisms. The surface textures are achieved by uniformly depositing a layer of indium-tin-oxide nanowhiskers on micro-grooved silicon substrates using electron-beam evaporation. The nanowhiskers facilitate optical transmission in the near-infrared by functioning as impedance matching layers with effective refractive indices gradually varying from 1 to 1.3. Materials with such unique refractive index characteristics are not readily available in nature. As a result, the solar cell with combined textures achieves over 90% external quantum efficiencies for a broad wavelength range of 460-980 nm, which is crucial to the development of advanced thin-substrate silicon solar cells.
随着硅光伏技术向薄片化发展，近红外波长的高效光学吸收变得极具挑战性。在这项工作中，我们提出了一种解决方案，采用微纳复合结构的表面织构来增加晶体硅光伏的近红外光捕获，并讨论了相关的抗反射和散射机制。通过电子束蒸发在微槽硅衬底上均匀沉积一层氧化铟锡纳米线来实现表面织构，纳米线作为阻抗匹配层，有效折射率逐渐从 1 变化到 1.3，从而促进近红外光的传输。具有这种独特折射率特性的材料在自然界中不容易获得。因此，具有复合织构的太阳能电池在 460-980nm 的宽波长范围内实现了超过 90%的外量子效率，这对先进的薄衬底硅太阳能电池的发展至关重要。
