作者
Guozheng Shi,Haibin Wang,Yaohong Zhang,Chen Cheng,Tianyu Zhai,Botong Chen,Xinyi Liu,Ryota Jono,Xinnan Mao,Yang Liu,Xuliang Zhang,Xufeng Ling,Yannan Zhang,Xing Meng,Yifan Chen,Steffen Duhm,Liang Zhang,Tao Li,Lu Wang,Shiyun Xiong,Takashi Sagawa,Takaya Kubo,Hiroshi Segawa,Qing Shen,Zeke Liu,Wanli Ma
摘要
Almost all surfaces sensitive to the ambient environment are covered by water, whereas the impacts of water on surface-dominated colloidal quantum dot (CQD) semiconductor electronics have rarely been explored. Here, strongly hydrogen-bonded water on hydroxylated lead sulfide (PbS) CQD is identified. The water could pilot the thermally induced evolution of surface chemical environment, which significantly influences the nanostructures, carrier dynamics, and trap behaviors in CQD solar cells. The aggravation of surface hydroxylation and water adsorption triggers epitaxial CQD fusion during device fabrication under humid ambient, giving rise to the inter-band traps and deficiency in solar cells. To address this problem, meniscus-guided-coating technique is introduced to achieve dense-packed CQD solids and extrude ambient water, improving device performance and thermal stability. Our works not only elucidate the water involved PbS CQD surface chemistry, but may also achieve a comprehensive understanding of the impact of ambient water on CQD based electronics.