EAPSI: Environmental Testing of Multi-Crystalline Thin Film Solar Cells

现有的太阳能电池材料比目前市场上由硅制成的技术效率更高。这些不是标准技术的原因是因为它们的制造成本非常昂贵。许多表现出高效率的材料都是通过非常缓慢和高纯度的技术生长出来的，这些技术既昂贵又耗能。因此，该项目将致力于创造和测量具有成本效益的III-V型太阳能电池在正常工作条件下的性能和行为，例如：不同的湿度水平，高温和低温，以及不同的光照。该研究将与新加坡南洋理工大学的原位透射电子显微镜（TEM）专家Martial Ducamp博士合作完成。这项研究的结果将确定低成本III-V型太阳能电池效率较低的可能原因，这反过来将使改进用于生产低成本、高效率太阳能电池的制造程序成为可能。将使用透射电子显微镜（TEM）和电子束感应电流（EBIC）来测试材料性能和电性能之间的关系。TEM观察原子间相互作用和键，而EBIC同时测量整个样品的局部载流子收集。通过将TEM图像与EBIC信号相关联，可以识别出某些结构、排列或键，从而导致良好或不良的性能。该项目还将评估设备运行条件下的TEM/EBIC相关性，以确定表现较弱的区域和由于实际环境因素而产生的潜在原因。随着对这些低性能区域的原因有了更深入的了解，将有可能对III-V生长过程进行迭代改进，直到可以制造出成本和效率都优化的设备。该奖项由美国国家科学基金会和新加坡国家研究基金会共同资助，隶属于东亚和太平洋暑期研究所项目，支持一名美国研究生进行暑期研究。

There exist solar cell materials that have higher efficiencies than the current market technology made from silicon. The reason these are not the standard technology is because they are exceedingly expensive to create. Many of the materials displaying high efficiencies are grown through very slow and high-purity techniques that are expensive and energy intensive. This project will therefore work to create and measure cost-effective III-V solar cells for their performance and behavior in normal operating conditions such as: different humidity levels, high and low temperatures, and varying light exposure. The research will be done in collaboration with Dr. Martial Ducamp, an expert in in-situ transmission electron microscopy (TEM), at Nanyang Technological University in Singapore, Singapore. The results of the study will identify possible causes of lower efficiencies in low-cost III-V solar cells, which will in turn make it possible to improve the manufacturing procedures used to produce lower cost, higher efficiency solar cells.The relationship between material properties and electrical performance will be tested using transmission electron microscopy (TEM) coupled with electron beam induced current (EBIC). TEM observes inter-atomic interactions and bonds, while, simultaneously, EBIC measures localized carrier collection throughout the sample. By correlating the TEM images with EBIC signal, certain structures, arrangements or bonds can be identified as resulting in good or bad performance. The project will also evaluate TEM/EBIC correlations under device operating conditions to identify weakly performing regions and potential causes that arise due to real, environmental factors. With a greater understanding of the causes of these low-performing regions, it will be possible to iterate making improvements to the III-V growth process until devices can be manufactured that are optimized both for cost and efficiency. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the National Research Foundation of Singapore.