EAGER: Stable and efficient perovskite solar cells

非技术：降低太阳能发电成本的关键挑战在于提高太阳能电池板的转换效率。串联太阳能电池由对不同波长的光作出反应的子电池制成，可以使太阳能电池板的效率提高一倍。然而，它们的部署受到高昂制造成本的限制。钙钛矿太阳能电池由于易于加工和化学调节吸收，有望用于低成本串联太阳能电池。大多数钙钛矿太阳能电池是由有机-无机混合材料制成的，这种材料在100°C以上的温度下分解，在潮湿的情况下降解。本项目的目标是开发一种热稳定到300℃，对水分相对不敏感的钙钛矿装置。该电池将是一种全无机结构，从而有可能提高其抗光诱导降解的稳定性。这种新装置很可能用于制造串联结电池，硅在串联结布置中充当底部电池。这项技术有可能提高太阳能转换的效率，降低其总体成本。该项目将为研究生和本科生提供一个重要的研究机会，包括那些来自STEM中代表性不足群体的学生。技术方面：该项目将开发基于新型无机钙钛矿-溴基无机钙钛矿合金Cs(Pb,Sn)Br3的光伏器件。带隙工程将使优化的串联结构的制造成为可能。加入锡可以将CsPbBr3的带隙从2.3 eV降低到1.9 eV，通过混合铯和铷可以进一步降低带隙。无机异质结层将用于制造器件。该材料将采用易于扩展的真空沉积工艺沉积。将对材料和器件进行详细的结构和电子表征，以了解器件的光伏性能。该装置将测试其抗湿热和光致降解的稳定性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Non-technical:The key challenge in reducing the cost of solar power lies in increasing the conversion efficiency of solar panels. Tandem solar cells are made from sub-cells that respond to different wavelengths of light and could double the efficiency of solar panels. Their deployment, however, has been limited by high fabrication costs. Perovskite solar cells hold promise for use in low-cost tandem solar cells due to ease of processing and chemical tuning of their absorption. Most perovskite solar cells are made from hybrid organic-inorganic materials which decompose at temperatures above 100°C and degrade in the presence of moisture. The aim of this project is to develop a perovskite device that is thermally stable to 300℃, and is relatively insensitive to moisture. The cell will be an all-inorganic structure, thereby potentially improving its stability against photo-induced degradation. The new device is likely to be useful for making tandem junction cells with silicon acting as the bottom cell in a tandem junction arrangement. The technology is likely to increase the efficiency of solar energy conversion and reduce its overall cost. The project will offer a significant opportunity for research to both graduate and undergraduate students, including those from underrepresented groups in STEM.Technical:This project will develop photovoltaic devices based on a new inorganic perovskite—a bromide based inorganic perovskite alloy, Cs(Pb,Sn)Br3. Bandgap engineering will enable the fabrication of an optimized tandem structure. The bandgap of the CsPbBr3 can be reduced from 2.3 eV to 1.9 eV by incorporating tin, with further reductions possible by mixing cesium and rubidium. Inorganic heterojunction layers will be used to fabricate the devices. The material will be deposited using vacuum deposition processes which are easily scalable. Detailed structural and electronic characterization of the material and the device will be undertaken to understand the photovoltaic performance of the device. The devices will be tested for their stability against moisture and heat and against photoinduced degradation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.