三维调制大孔黑硅及其在太阳能转换中的应用

项目名称： 三维调制大孔黑硅及其在太阳能转换中的应用

项目编号： No.61204074

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 信息四处

项目作者： 敖献煜

作者单位： 华南师范大学

项目金额： 30万元

中文摘要： 依靠硅等半导体材料，太阳能可被直接转换为电能或化学能。目前有大量研究将腐蚀出纳米线或纳米孔的单晶硅片用于光伏太阳能电池，以期提高光电转换效率。然而，在硅片表面制备纳米结构势必会增加表面复合损耗，所增加的光学吸收有可能无法补偿由此带来的额外的表面复合损耗。本项目旨在通过简单可控的电化学方法获得用来减反和陷光的硅基微纳混合结构，确保光吸收的增加超过表面复合损耗的增加，辅以共形pn结等有效的载流子抽取机制，从而提高硅基光伏电池的转换效率。三维调制的大孔黑硅是在微米直径的孔上叠加纳米尺度的渐变结构，以分别改善近红外和可见波段的光学特性，能实现宽波长范围的光反射抑制和陷光，尤其能增强带隙附近的光吸收。同样厚度的大孔黑硅比纳米孔/纳米线结构有更高的吸收效率，更小的表面积亦即更低的表面复合损耗，因此有望进一步提高太阳能的转换效率。

中文关键词： 黑硅；硅纳米线；光伏太阳能电池；黑色吸光膜；光解水

英文摘要： Solar energy can be converted into electricity or chemical energy by using semiconductors such as silicon. There have been a lot of papers considering nanowires/nanoholes etched on silicon wafer for potential applications in photovoltaics. Texturing the silicon surface can reduce the total reflection and increase the surface area. However, increased surface area also means increased surface recombination rate. An obvious enhancement in conversion efficiency can be observed only when the increase in the optical absorption heavily outweighs the increase in the surface recombination rate. In this proposal, we will develop three-dimensionally modulated macroporous black silicon by using the well-established and controllable electrochemical etching technology, form conformal solid or liquid junctions, and study their applications in photovoltaics, combining the benefits of low reflection surface, light trapping structure, and conformal junctions, in order to enhance the conversion efficiency. In comparison with nanowires or nanoholes in silicon, macroporous black silicon is a hybrid of nano- and micro-structures, such that it can suppress light reflection in a broader band, and especially, it can highly enhance the light absorption near the band gap of silicon. Moreover, for the same thickness, macroporous silicon ha

英文关键词： Black silicon；Silicon nanowire；Photovoltaics；Black absorber；Photocatalytic water splitting