Gettering of impurities in silicon: delivering quantitative understanding to improve photovoltaics

去除硅中的杂质：提供定量理解以改进光伏发电

基本信息

批准号：
EP/J01768X/2
负责人：
John Murphy
金额：
$ 10.81万
依托单位：
University of Warwick
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2013
资助国家：
英国
起止时间：
2013 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FJ01768X%2F2
关键词：
Gettering impurities silicon delivering quantitative

项目摘要

Photovoltaics have the potential to supply all the world's energy needs. The market for photovoltaics is dominated by cells made from crystalline silicon, which account for more than 80% of today's production. Whilst other technologies are being researched, silicon's abundance, chemical stability, density, band gap and non-toxic nature mean that is certain to play a leading role in at least the medium term. More than half of bulk silicon solar cells are fabricated from multicrystalline silicon (mc-Si) wafers. Although mc-Si photovoltaics have lower efficiencies than their single-crystal counterparts, their substantially lower production costs means the technologies have equal commercial viability at present. Mc-Si is produced by casting, often using a low grade feedstock, and is consequently packed with extended defects (dislocations, grain boundaries and precipitates) and transition metal impurity point defects. Recombination of photogenerated charge carriers at such defects is a major reason for the reduced efficiency of mc-Si cells. Gettering processes are routinely used either to redistribute the defects or remove them from the material. However, such processes are not completely effective. One of the major reasons for this is that the interaction between defects prevents them being gettered. This project aims to further the fundamental understanding of defect interactions in mc-Si. The thermodynamics of interactions between transition metals (particularly iron) and extended defects (particularly dislocations and oxide precipitates) will be studied experimentally. Passivation of key extended defects will also be investigated. The fundamental knowledge obtained should allow the development of new or modified gettering processes with the ultimate aim of facilitating the use of dirtier (hence cheaper) feedstocks for silicon photovoltaics.

光伏电源有可能满足世界所有能源需求。光伏市场的市场由结晶硅制成的细胞主导，该细胞占当今产量的80％以上。尽管正在研究其他技术，但硅的丰度，化学稳定性，密度，带隙和无毒性质意味着肯定会在至少中期中发挥领导作用。超过一半的散装硅太阳能电池是由多晶硅（MC-SI）晶圆制成的。尽管MC-SI光伏的效率低于单晶的效率，但它们的生产成本大大降低，这意味着该技术目前具有相同的商业生存能力。 MC-SI是通过铸造产生的，通常使用低级原料，因此挤满了延长的缺陷（位错，晶界和沉淀物）和过渡金属杂质点缺陷。在这种缺陷下，光生荷载载体的重组是MC-SI细胞效率降低的主要原因。通常使用获取过程来重新分布缺陷或将其从材料中删除。但是，这样的过程并不完全有效。这样做的主要原因之一是，缺陷之间的相互作用阻止了它们被陷入困境。该项目旨在进一步了解MC-SI中缺陷相互作用的基本理解。将通过实验研究过渡金属（尤其是铁）和扩展缺陷（尤其是脱位和氧化物沉淀）之间相互作用的热力学。还将研究关键扩展缺陷的钝化。获得的基本知识应允许开发新的或修改的获取过程，其最终目的是促进使用更脏（因此更便宜）用于硅光伏的原料。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Superacid-Treated Silicon Surfaces: Extending the Limit of Carrier Lifetime for Photovoltaic Applications

DOI：
10.1109/jphotov.2017.2751511
发表时间：
2017-10
期刊：
IEEE Journal of Photovoltaics
影响因子：
3
作者：
N. Grant;T. Niewelt;N. Wilson;Evangeline C. Wheeler-Jones;J. Bullock;M. Al-Amin;M. Schubert;A. V. van Veen;A. Javey;J. D. Murphy
通讯作者：
N. Grant;T. Niewelt;N. Wilson;Evangeline C. Wheeler-Jones;J. Bullock;M. Al-Amin;M. Schubert;A. V. van Veen;A. Javey;J. D. Murphy

Low-Temperature Saw Damage Gettering to Improve Minority Carrier Lifetime in Multicrystalline Silicon

低温锯损伤吸杂可提高多晶硅中少数载流子的寿命