Liu Dong, Wang Lin, Cui Qingyu, Guo L Jay
MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science and Technology Nanjing 210094 China.
Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI 48109 USA.
Adv Sci (Weinh). 2018 Aug 26;5(10):1800836. doi: 10.1002/advs.201800836. eCollection 2018 Oct.
The achievement of perfect light absorption in ultrathin semiconductor materials is not only a long-standing goal, but also a critical challenge for solar energy applications, and thus requires a redesigned strategy. Here, a general strategy is demonstrated both theoretically and experimentally to create a planar metasurface absorber comprising a 1D ultrathin planar semiconductor film (replacing the 2D array of subwavelength elements in classical metasurfaces), a transparent spacer, and a metallic back reflector. Guided by derived formulisms, a new type of macroscopic planar metasurface absorber is experimentally demonstrated with light near-perfectly and exclusively absorbed by the ultrathin semiconductor film. To demonstrate the power and simplicity of this strategy, a prototype of a planar metasurface solar cell is experimentally demonstrated. Furthermore, the device model predicts that a colored planar metasurface perovskite solar cell can maintain 75% of the efficiency of its black counterpart despite the use of a perovskite film that is one order of magnitude thinner. The displayed cell colors have high purities comparable to those of state-of-the-art color filters, and are insensitive to viewing angles up to 60°. The general theoretical framework in conjunction with experimental demonstrations lays the foundation for designing miniaturized, planar, and multifunctional solar cells and optoelectronic devices.
在超薄半导体材料中实现完美的光吸收不仅是一个长期目标，也是太阳能应用面临的一项关键挑战，因此需要重新设计策略。在此，从理论和实验两方面展示了一种通用策略，用于创建一种平面超表面吸收体，该吸收体由一维超薄平面半导体薄膜（取代传统超表面中的二维亚波长元件阵列）、透明间隔层和金属背反射器组成。在推导公式的指导下，通过实验展示了一种新型宏观平面超表面吸收体，其光几乎完全且仅被超薄半导体薄膜吸收。为了证明该策略的有效性和简便性，通过实验展示了平面超表面太阳能电池的原型。此外，器件模型预测，尽管使用的钙钛矿薄膜薄了一个数量级，但彩色平面超表面钙钛矿太阳能电池仍可保持其黑色对应物75%的效率。所展示的电池颜色具有与最先进的彩色滤光片相当的高纯度，并且在高达60°的视角范围内不敏感。通用的理论框架与实验演示为设计小型化、平面化和多功能太阳能电池及光电器件奠定了基础。
