无机配体介导尺寸、结构和性质可调的铜锌锡硫纳米晶的合成

Cu2ZnSnS4 (CZTS) is consider as one of promising materials for the new generation of solar cells, due to its near-optimal direct band gap, large absorption coefficient, containing of earth-abundant elements and environmentally friendly nature. Cu2ZnSnS4 nanocrystals can be used as "nanocrystal ink" that is coated on a substrate to yield low-cost solar cells. In the synthesis of Cu2ZnSnS4 nanocrystals, organic compounds with long hydrocarbon chains used as the ligands always create insulating layers (or barriers) around nanocrystals which block electronic com munication (or carrier transport) between nanocrystals, thus limiting the usefulness of nanocrystals in high efficiency solar cells. Inorganic ligands bond to metal atoms at the nanocrystals surface by coordinated or electrostatic interactions and play a key role in the nucleation and growth of colloidal nanocrystals. These ligands promote electronic communication (or carrier transport) between the nanocrystals, and also benefit for the growth and stabilization of the nanocrystals. This proposed research will investigate inorganic ligands mediated synthesis of Cu2ZnSnS4 nanocrystals with tunable sizes, shapes and properties. The mediated mechanism of inorganic ligands on nanocrystals synthesis, influence of inorganic ligands on Cu2ZnSnS4 nanocrystals photoelectric properties, screening of nanocrystals suitable for solar cells will also be studied. Results of this research will help better understand the relationships between nanocrystals and performance of solar cells, thus benefit Cu2ZnSnS4 based solar cells.

铜锌锡硫具有与太阳光谱匹配的禁带宽度，超高的光吸收系数及在地壳中含量丰富对环境友好的特点，被认为是新一代太阳能电池的候选材料。铜锌锡硫纳米晶可直接用作"纳米晶墨水"低成本印制太阳能薄膜电池。铜锌锡硫纳米晶制备过程中所采用长链有机物配体在纳米晶的周围构建了一个微绝缘环境，严重阻碍了电子（载流子）的迁移，也限制了纳米晶太阳能电池效率的提高。无机配体通过与纳米晶金属间的配位作用修饰、稳定纳米晶并调控其生长过程，无机配体导电的性质则解决了电子迁移的问题。本项目利用无机配体介导合成不同尺寸、结构和性质的铜锌锡硫纳米晶，并研究无机配体介导原理及其对纳米晶光电性能的影响，筛选适用于太阳能电池的铜锌锡硫纳米晶。本研究将加深理解纳米晶与太阳能电池性能的关系，为深入研究铜锌锡硫太阳能电池提供技术支持。

铜锌锡硫具有与太阳光谱匹配的禁带宽度，超高的光吸收系数及在地壳中含量丰富对环境友好的特点，被认为是新一代太阳能电池的候选材料。铜锌锡硫纳米晶可直接用作“纳米晶墨水”低成本印制太阳能薄膜电池。在本项目的资助下，项目组主要开展了以下几个方面的研究：1. 采用一锅法制备了铜锌锡硫纳米晶，通过实验条件的控制，实现对铜锌锡硫纳米晶形貌、大小及光电性质的调控。2.直接在水溶液中合成制备水溶性铜锌锡硫纳米晶。3.筛选适用于太阳能电池的铜锌锡硫。4将铜锌锡硫应用于太阳电池器件组装并进行性能表征。