太阳能电池的光学管理基本理念

Basic concepts of light management for photovoltaics

活性层吸光能力和载流子传输能力之间的折衷是制约太阳能电池效率提升和成本降低的重要因素之一.特别是随着太阳能电池的薄膜化发展趋势,活性层吸光能力不足所导致的光学损失显得越来越重要.而光学管理技术能够有目的地调控入射光谱,在太阳能电池中获得可控的光场传输和能量分布,在实现光吸收增强的同时还保持了活性层优秀的电学传输性能,正是克服这一折衷的有效工具.本文从光线光学、传统波动光学和纳米光子学的视角详细阐述了典型陷光结构的光约束和增强机制,展望了光学管理技术的发展趋势.

The fundamental tradeoff between light absorption and carrier collection ranks as one o[ the most important factors for the low-cost and high efficiency photovoltaic devices. As solar cells become thinner, absorption losses become more important because a thinner active layer absorbs much less light. Fortunately, light management has emerged as a powerful approach for overcoming this tradeoff, because which permits the manipulation of incident optical fields, and could control of the light propaga- tion and energy distribution in photovoltaic devices, ultimately achieves absorption enhancements while without sacrificing the electrical performance in the active layer. From three perspectives including ray optics, traditional wave optics and nanophotonics, the basic physical concepts of light confinement and enhancement in typical light trapping structures are introduced in detail, and the trend of light manage- ment is also presented in this paper.