COLLABORATIVE RESEARCH: Understanding and harnessing structural defects, doping, passivation, and alloying to increase Voc and efficiency of CdTe solar cells

职务名称：通过创新工艺设计推进光伏技术非技术说明：本项目旨在开发材料科学和器件工程领域的新知识，以进一步提高基于CdTe的低成本光伏（PV）技术的性能。 尽管光伏技术在过去二十年中实现了巨大的市场增长和价格下降，但光伏发电仍占我们总用电量的不到1%;通过提高设备性能，可以进一步降低成本，从而加快光伏的部署。该项目将研究几种工艺路线，以提高CdTe电池的输出电压，这是实现接近理想性能的剩余挑战。 本研究旨在最大限度地减少晶界和其他结构缺陷的负面影响，以改善控制CdTe电池输出电压的关键材料性能。 重点将是研究元素杂质，特别是磷（P）掺杂，及其与CdTe薄膜及其合金中的晶界和其他二维结构缺陷的相互作用。这两个机构的研究生将获得薄膜器件制造，晶体生长以及材料和器件表征的先进方法的经验。该项目还将影响K-12学生，并提供薄膜太阳能电池的教育资源和光伏教育材料。PI和副研究生将继续向初中和高中学生提供实践太阳能电池教学。技术描述：该项目的主要目标是创造提高CdTe PV输出电压所需的基础知识和加工技术。本研究的主要目的是：（1）研究孤立晶界在大晶粒材料中的作用，并利用这些发现来调整多晶薄膜的性能;（2）研究V族掺杂剂与后沉积工艺对p型掺杂的综合作用;（3）通过合金化CdTe（Se，S）抑制结构缺陷来增强p型掺杂;（4）研究掺杂剂对p型掺杂的影响。（4）通过合金化，在关键器件界面（例如主结和背接触）处降低界面复合。上述目标将通过一个整体的方法，将包括大毫米晶粒尺寸的散装材料，设备质量的多晶薄膜，和国家的最先进的设备结构的调查。该项目的实验部分将植根于基础材料研究，并扩展到设备工程。 这些活动将使用器件物理模型来指导，以预测太阳能电池的性能。该项目的结果可能对太阳能电池制造产生直接影响，并可能在提高效率和降低多晶CdTe太阳能电池成本方面产生范式转变的影响。

Title: Advancing photovoltaic technologies through innovative process designNon-Technical Description:This project aims at developing new knowledge in the areas of materials science and device engineering to further advance the performance of the low cost photovoltaic (PV) technology based on CdTe. Despite the tremendous market growth and price reduction demonstrated by PV technologies over the last two decades, PV-generated electricity remains below 1% of our total electricity usage; further cost reduction could be achieved through higher device performance leading to accelerated deployment of PV. The project will investigate several processing routes to improve the output voltage of the CdTe cell, which is the remaining challenge to achieving near ideal performance. This research seek to minimize the negative impact of grain boundaries and other structural defects, in order to improve key material properties which control the output voltage of CdTe cells. The focus will be on studying elemental impurities, specifically phosphorous (P) doping, and its interaction with grain boundaries and other 2D structural defects in CdTe films and their alloys. Graduate students at both institutions will gain experience in thin film device fabrication, crystal growth, and advanced methods of characterization of materials and devices. This project will also impact students from K-12 and provide educational resources on thin film solar cells and materials on PV education. The PIs and associate graduate students will continue hands-on solar cell teaching outreach to middle and high school students. Technical Description:The main goal of this project is to create the fundamental knowledge and processing techniques required to advance the output voltage of CdTe PV. This research has the following objectives:(1) investigate the effect of isolated grain boundaries in large mm grain size materials, and use the findings to tailor the properties of polycrystalline thin films; (2) investigate the combined effect of group V dopant(s) with post-deposition processing techniques on the net p-type doping; (3) enhance p-type doping by suppressing structural defects through alloying CdTe(Se,S); (4) lower interface recombination at critical device interfaces, such as the main junction and back contact, through alloying. The above goals will be pursued through a holistic approach that will include the investigation of large mm grain size bulk materials, device quality polycrystalline thin films, and state-of-the-art device structures. The experimental component of the project will be rooted in fundamental material studies and expanded to device engineering. The activities will be guided using device physics models to predict solar cell performance. Results from this project may have a direct impact on solar cell manufacturing and could lead to a paradigm shift impact in terms of improving efficiency and decreasing cost of polycrystalline CdTe-based solar cells.