铜锌锡硫硒太阳电池水性前驱体溶液中的配位调控

Coordination engineering of Cu-Zn-Sn-S aqueous precursor for efficient kesterite solar cells

水性前驱体溶液法在制备半导体薄膜材料,尤其是新型铜锌锡硫硒(CZTSSe)薄膜方面,极具成本和环保优势.本文利用巯基乙酸分子配体制备CZTSSe水性前驱溶液,并系统研究了该体系中的配位化学机制.通过去质子化过程,对金属-巯基乙酸的配位结构进行了调控,实现了金属阳离子与巯基阴离子充分配位,从而释放了亲水的羧基以形成稳定的水性溶液.最终,作者制备出了光电转换效率达到12.3%(认证效率12.0%)的CZTSSe太阳电池,是目前非联胺体系中的最高效率.本工作是CZTSSe电池在溶液法制备上的一个显著进步,对于CZTSSe及其他金属硫化物光伏电池的发展具有重要意义.

Aqueous precursors provide an alluring approach for low-cost and environmentally friendly production of earth-abundant Cu2ZnSn(S,Se)4(CZTSSe)solar cells.The key is to find an appropriate molecular agent to prepare a stable solution and optimize the coordination structure to facilitate the subsequent crystallization process.Herein,we introduce thioglycolic acid(TGA),which possesses strong coordination(SH)and hydrophilic(COOH)groups,as the agent and use deprotonation to regulate the coordination competition within the aqueous solution.Ultimately,metal cations are adequately coordinated with thiolate anions,and carboxylate anions are released to become hydrated to form an ultrastable aqueous solution.These factors have contributed to achieving CZTSSe solar cells with an efficiency as high as 12.3%(a certified efficiency of 12.0%)and providing an extremely wide time window for precursor storage and usage.This work represents significant progress in the non-toxic solution fabrication of CZTSSe solar cells and holds great potential for the development of CZTSSe and other metal sulfide solar cells.