当前位置: X-MOL 学术Adv. Funct. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Facet Control for Trap‐State Suppression in Colloidal Quantum Dot Solids
Advanced Functional Materials ( IF 19.0 ) Pub Date : 2020-04-06 , DOI: 10.1002/adfm.202000594
Yong Xia 1 , Wei Chen 2, 3 , Peng Zhang 4 , Sisi Liu 1 , Kang Wang 1 , Xiaokun Yang 5 , Haodong Tang 3 , Linyuan Lian 1 , Jungang He 6 , Xinxing Liu 5 , Guijie Liang 7 , Manlin Tan 8 , Liang Gao 5 , Huan Liu 1 , Haisheng Song 5 , Daoli Zhang 1 , Jianbo Gao 9 , Kai Wang 3 , Xinzheng Lan 1 , Xiuwen Zhang 4 , Peter Müller‐Buschbaum 2, 10 , Jiang Tang 5 , Jianbing Zhang 1, 5
Affiliation  

Trap states in colloidal quantum dot (QD) solids significantly affect the performance of QD solar cells, because they limit the open‐circuit voltage and short circuit current. The {100} facets of PbS QDs are important origins of trap states due to their weak or missing passivation. However, previous investigations focused on synthesis, ligand exchange, or passivation approaches and ignored the control of {100} facets for a given dot size. Herein, trap states are suppressed from the source via facet control of PbS QDs. The {100} facets of ≈3 nm PbS QDs are minimized by tuning the balance between the growth kinetics and thermodynamics in the synthesis. The PbS QDs synthesized at a relatively low temperature with a high oversaturation follow a kinetics‐dominated growth, producing nearly octahedral nanoparticles terminated mostly by {111} facets. In contrast, the PbS QDs synthesized at a relatively high temperature follow a thermodynamics‐dominated growth. Thus, a spherical shape is preferred, producing truncated octahedral nanoparticles with more {100} facets. Compared to PbS QDs from thermodynamics‐dominated growth, the PbS QDs with less {100} facets show fewer trap states in the QD solids, leading to a better photovoltaic device performance with a power conversion efficiency of 11.5%.

中文翻译:

胶体量子点固体中陷阱状态抑制的方面控制

胶体量子点(QD)固体中的陷阱状态会严重影响QD太阳能电池的性能,因为它们会限制开路电压和短路电流。PbS QD的{100}面是钝态弱或缺失的重要陷阱源。然而,先前的研究集中在合成,配体交换或钝化方法上,而忽略了对于给定点尺寸的{100}面的控制。这里,通过PbS QD的方面控制从源抑制了陷阱状态。通过调整合成过程中生长动力学和热力学之间的平衡,使≈3nm PbS QD的{100}面最小化。在较低的温度下具有较高的过饱和度而合成的PbS QD遵循动力学主导的生长,产生几乎八面体的纳米粒子,这些纳米粒子主要由{111}面终止。相反,在较高温度下合成的PbS QD遵循热力学主导的生长。因此,优选球形,产生具有更多{100}小平面的截短的八面体纳米颗粒。与热力学主导的PbS QD相比,{100}面较少的PbS QD在QD固体中显示的陷阱态更少,从而带来了更好的光伏器件性能,功率转换效率为11.5%。
更新日期:2020-04-06
down
wechat
bug