Interfacial Engineering of Solution-Processed Thin-Film Photovoltaic Devices

溶液处理薄膜光伏器件的界面工程

• 批准号: 2610807
• 金额: --
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2610807
• 关键词: Interfacial; Engineering; Solution; Processed; Thin

The UK has set a legally binding target of net carbon zero by 2050 in every aspect of the economy and delivering sustainable and green solar electricity generation will be crucial in this transformation. Crystalline Si currently dominates the solar industry, representing approximately 95 % of the solar modules sold today. However, due to its low photon absorption coefficient and indirect bandgap, thicknesses up to 350 m are needed, making crystalline Si unsuitable for thin-film applications. Thin-film photovoltaic (PV) materials on flexible substrates will allow for the integration of solar energy conversion in buildings and infrastructure in urban environments, which is a key area of expansion in solar energy to meet required environmental targets. Cu2ZnSn(S,Se)4 (CZTSSe) is a non-toxic, inorganic thin-film material with desirable PV properties due to its tuneable direct bandgap between 1.0 - 1.5 eV and 20 % theoretical power conversion efficiency (PCE) under AM1.5G illumination. However, CZTSSe is currently limited by significant voltage losses, which have been linked to structural disorder including antisites defects, secondary phases, and point defect clusters, hindering the PCE. This PhD is part of a collaboration between the universities of Bristol, Northumbria and Loughborough on the SolPV project, funded by EPSRC, and industrial partners of Centre of Process Innovation, Johnson Matthey, BAE systems and M-Solv. The main purpose of this PhD is to perform interfacial engineering of the p-n junction between the CZTSSe absorber layer and buffer layer, using atomic layer deposition, to achieve record breaking efficiencies of greater than 15 %. CdS has been extensively used as a buffer layer for CZTSSe solar devices as it is an established buffer material for the most advanced technology of CuInxGa1-x(S,Se)2 (CIGS). Although CdS has worked as an efficient buffer layer in both CZTSSe and CIGS, Cd is toxic and cannot be released into the environment, therefore, a suitable replacement is required. In- and Zn-based oxysulfide alternatives will be investigated as possible replacements. Another aim of the project is to control crystallisation and composition of the absorber material and reduce the formation of detrimental defects, deep Sn trap states and carbon impurities by optimising the fabrication methodology. Bulk and surface composition and structure of the thin-films will be examined by electron microscopy techniques, Raman microscopy and Energy-Filtered Photoemission electron microscopy (EF-PEEM). EF-PEEM can provide surface electronic mapping of local effective work functions at the absorber-buffer junction, allowing for unique and vital electronic information. The focus of this research will be to confirm the PCE of CZTSSe solar cells will go beyond 15 %, while also using scalable manufacturing routes to ensure a smooth transition into industrial applications. This project falls within the EPSRC 'Solar Technology' research area.

到2050年，英国在经济的各个方面都设定了净碳零具有法律约束力的目标，并在这种转变中提供可持续的和绿色的太阳能发电至关重要。 Crystalline SI目前在太阳能行业中占主导地位，占当今售出的太阳能模块的95％。但是，由于其低光子吸收系数和间接带隙，需要350 m的厚度，从而使晶体SI不适合薄膜应用。柔性基材上的薄膜光伏（PV）材料将允许在城市环境中在建筑物和基础设施中整合太阳能转换，这是太阳能扩张的关键领域，以满足所需的环境目标。 Cu2ZNSN（S，SE）4（CZTSSE）是一种无毒的无机薄膜材料，由于其在AM1.5G照明下的1.0-1.5 eV和20％理论功率转换效率（PCE）之间的可调性直接带隙，具有理想的PV特性。但是，CZTSSE目前受到明显的电压损耗的限制，这些电压损耗与结构性障碍有关，包括反异地缺陷，次级阶段和点缺陷簇，阻碍了PCE。该博士是由EPSRC资助的Bristol，Northumbria和Loughborough大学合作的一部分，以及Process Innovation Center Innovation，Johnson Matthey，Bae Systems和M-Solv的工业合作伙伴。该博士学位的主要目的是使用原子层沉积在CZTSSE吸收层和缓冲层之间对P-N结的界面工程，以实现大于15％的记录破坏效率。 CD已被广泛用作CZTSSE太阳能设备的缓冲层，因为它是Cuinxga1-X（S，SE）2（CIGS）最先进技术的已建立的缓冲材料。尽管CD在CZTSSE和CIGS中都是有效的缓冲层，但CD是有毒的，不能释放到环境中，因此需要合适的替换。将根据可能的替代品研究基于内部和Zn的氧气硫化物替代品。该项目的另一个目的是通过优化制造方法来控制吸收材料的结晶和组成，并减少有害缺陷，深Sn陷阱状态和碳杂质的形成。将通过电子显微镜技术，拉曼显微镜和能量过滤光发射电子显微镜（EF-eem）检查薄膜的散装和表面组成和结构。 EF-eem可以在吸收缓冲器连接处提供局部有效工作功能的表面电子映射，从而提供独特而重要的电子信息。这项研究的重点是确认CZTSSE太阳能电池的PCE将超过15％，同时还使用可扩展的制造途径来确保平稳过渡到工业应用。该项目属于EPSRC“太阳能技术”研究领域。