In situ X-ray radiography and diffraction imaging of the growth of silicon for photovoltaic applications

光伏应用硅生长的原位 X 射线照相和衍射成像

• 批准号: 400343964
• 负责人: Dr. Maike Becker
• 金额: --
• 依托单位: Institut für Materialphysik im Weltraum
• 依托单位国家: 德国
• 项目类别: Research Fellowships
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/400343964?language=en
• 关键词: situ; ray; radiography; diffraction; imaging

Crystalline silicon based photovoltaics (PV) is one of the key technologies on the way into the age of renewable energy. Increasing the energy efficiency of solar cells and at the same time reducing the production costs is the major challenge of the PV industry. One way to achieve this is to improve the crystalline quality of the silicon wafers. The presence of grain boundaries, dislocations and impurities significantly lowers the PV performance. Such defects act as recombination sites for electrons and holes and therefore reduce the solar-cell efficiency. Impurities segregate at higher order grain boundaries during the solidification process and can modify the solid-liquid interface creating structural defects. Consequently, controlling the density and nature of defects during silicon growth will result in better solar-cell performances.To achieve this, a fundamental understanding of the mechanisms governing defect generation is essential. We will use a unique combination of in-situ X-ray radiography, diffraction imaging and different post-mortem techniques, to reveal the generation of different defects during silicon solidification and to study their impact on PV properties. Synchrotron X-ray radiography enables us to observe the solid-liquid interface during crystal growth. With this technique the generation of new grains at grain boundary grooves can be studied. Diffraction imaging gives information on dislocations and strain fields in the growing crystals. The implementation of a new camera system of high spatial and temporal resolution will allow us to track a selected diffraction spot in greater detail so that the propagation of dislocations and their interaction with different grain boundary types (random angle, twin) can be studied. This will help us to understand the influence of different grain boundary types on the emission and also on the blocking of dislocations which is crucial when aiming at improving the product quality. Additionally, the impact of impurities on the PV properties will be analyzed in more detail by studying samples that contain different amounts of light impurities. As impurities are usually introduced during the fabrication process it is essential to investigate their interaction with dislocations and different grain boundary types.In general, this study aims at deepening the knowledge about defect generation in directionally solidified silicon and its influence on the PV properties. The new information might indicate potential improvements for the fabrication of crystalline silicon solar cells.

晶体硅光伏技术是可再生能源时代的关键技术之一。提高太阳能电池的能源效率，同时降低生产成本是光伏行业面临的主要挑战。实现这一点的一种方法是提高硅晶片的结晶质量。晶界、位错和杂质的存在显著降低了PV性能。这些缺陷作为电子和空穴的复合位点，因此降低太阳能电池效率。杂质在凝固过程中在高阶晶界处偏析，并且可以修改固液界面，从而产生结构缺陷。因此，在硅生长过程中控制缺陷的密度和性质将导致更好的太阳能电池性能。我们将使用原位X射线照相术，衍射成像和不同的事后分析技术的独特组合，揭示硅固化过程中不同缺陷的产生，并研究它们对PV特性的影响。同步辐射X射线照相术使我们能够观察晶体生长过程中的固液界面。利用这种技术，可以研究晶界凹槽处新晶粒的生成。衍射成像给出了生长晶体中位错和应变场的信息。高空间和时间分辨率的新相机系统的实施将使我们能够更详细地跟踪选定的衍射点，以便可以研究位错的传播及其与不同晶界类型（随机角，孪晶）的相互作用。这将有助于我们了解不同晶界类型对发射的影响，以及对位错的阻挡，这在提高产品质量时至关重要。此外，将通过研究含有不同量轻杂质的样品，更详细地分析杂质对PV特性的影响。由于杂质通常是在制造过程中引入的，因此有必要研究它们与位错和不同晶界类型的相互作用。总的来说，本研究旨在加深对定向凝固硅中缺陷产生及其对光伏性能影响的认识。新的信息可能表明晶体硅太阳能电池制造的潜在改进。

项目成果

Simultaneous X-ray radiography and diffraction topography imaging applied to silicon for defect analysis during melting and crystallization

• DOI: 10.1107/s1600576719013050
• 发表时间: 2019-12-01
• 期刊: JOURNAL OF APPLIED CRYSTALLOGRAPHY
• 影响因子: 6.1
• 作者: Becker, Maike;Regula, Gabrielle;Mangelinck-Noel, Nathalie
• 通讯作者: Mangelinck-Noel, Nathalie

Investigation of subgrains in directionally solidified cast mono-seeded silicon and their interactions with twin boundaries

• DOI: 10.1016/j.solmat.2020.110817
• 发表时间: 2020-12
• 期刊: Solar Energy Materials and Solar Cells
• 影响因子: 6.9
• 作者: M. Becker;E. Pihan;F. Guittonneau;L. Barrallier;G. Regula;H. Ouaddah;G. Reinhart;N. Mangelinck-Noël

X-ray Based in Situ Investigation of Silicon Growth Mechanism Dynamics—Application to Grain and Defect Formation

基于 X 射线的硅生长机制动力学原位研究在晶粒和缺陷形成中的应用

• DOI: 10.3390/cryst10070555
• 发表时间: 2020
• 作者: Hadjer Ouaddah;Maike Becker;Thècle Riberi-Béridot;Maria Tsoutsouva;Vasiliki Stamelou;Gabrielle Regula;Guillaume Reinhart;Isabelle Périchaud
• 通讯作者: Isabelle Périchaud