廖良生教授课题组王亚坤同学在Nature Nanotechnology上发表合作文章

题目：

Bipolar-shell resurfacing for blue LEDs based on strongly confined perovskite quantum dots

作者：

Yitong   Dong,^1,† Ya-Kun Wang,^1,2,† Fanglong Yuan,^1,3,† Andrew Johnston,¹ Yuan Liu,¹ Dongxin Ma,¹   Min-Jae Choi¹, Bin Chen,¹ Mahshid Chekini,⁴   Se-Woong Baek,¹ Laxmi Kishore Sagar,¹ James Fan,¹ Yi Hou,¹ Mingjian Wu,⁵ Seungjin Lee,¹ Bin Sun,¹ Sjoerd Hoogland,¹ Rafael Quintero-Bermudez,¹ Hinako Ebe,¹ Petar Todorovic,¹ Filip Dinic,⁶   Peicheng Li,³ Hao Ting Kung,³ Makhsud I. Saidaminov¹, Eugenia Kumacheva,⁴ Erdmann Spiecker,⁵ Liang-Sheng Liao,² Oleksandr Voznyy,⁶ Zheng-Hong Lu^3,* & Edward H. Sargent^1,*

单位：

¹Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario, Canada.

²Institute of Functional Nano and Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, PR China.

³Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario, Canada.

⁴Department of Chemistry, University of Toronto, Toronto, Ontario,   Canada.

⁵Centre for Nanoanalysis and Electron Microscopy (CENEM) and Institute of Micro- and Nanostructure Research, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.

⁶Department of Physical and Environmental Sciences, University of Toronto Scarborough, Scarborough, Ontario, Canada.

摘要：

Colloidal quantum dot (QD) solids are emerging semiconductors that have been actively explored in fundamental studies of charge transport and for applications in optoelectronics. Forming high-quality QD solids — necessary for device fabrication — requires substitution of the long organic ligands used for synthesis with short ligands that provide increased QD coupling and improved charge transport. However, in perovskite QDs, the polar solvents used to carry out the ligand exchange decompose the highly ionic perovskites. Here we report perovskite QD resurfacing to achieve a bipolar shell consisting of an inner anion shell, and an outer shell comprised of cations and polar solvent molecules. The outer shell is electrostatically adsorbed to the negatively charged inner shell. This approach produces strongly confined perovskite QD solids that feature improved carrier mobility (≥0.01 cm² V⁻¹ s⁻¹)   and reduced trap density relative to previously reported low-dimensional perovskites. Blue-emitting QD films exhibit photoluminescence quantum yields exceeding 90%. By exploiting the improved mobility, we have been able to fabricate CsPbBr₃ QD-based efficient blue and green light-emitting diodes. Blue devices with reduced trap density have an external quantum efficiency of 12.3%; the green devices achieve an external quantum efficiency of 22%.

影响因子：

31.538

分区情况：

一区

链接：

https://www.nature.com/articles/s41565-020-0714-5