Solution Synthesis Approach to Colloidal Cesium Lead Halide Perovskite Nanoplatelets with Monolayer-Level Thickness Control

详细信息    查看全文

• 作者：Quinten A. Akkerman ; Silvia Genaro Motti ; Ajay Ram Srimath Kandada ; Edoardo Mosconi ; Valerio D’Innocenzo ; Giovanni Bertoni ; Sergio Marras ; Brett A. Kamino ; Laura Miranda ; Filippo De Angelis ; Annamaria Petrozza ; Mirko Prato ; Liberato Manna
• 刊名：Journal of the American Chemical Society
• 出版年：2016
• 出版时间：January 27, 2016
• 年：2016
• 卷：138
• 期：3
• 页码：1010-1016
• 全文大小：466K
• ISSN：1520-5126

文摘

We report a colloidal synthesis approach to CsPbBr₃ nanoplatelets (NPLs). The nucleation and growth of the platelets, which takes place at room temperature, is triggered by the injection of acetone in a mixture of precursors that would remain unreactive otherwise. The low growth temperature enables the control of the plate thickness, which can be precisely tuned from 3 to 5 monolayers. The strong two-dimensional confinement of the carriers at such small vertical sizes is responsible for a narrow PL, strong excitonic absorption, and a blue shift of the optical band gap by more than 0.47 eV compared to that of bulk CsPbBr₃. We also show that the composition of the NPLs can be varied all the way to CsPbBr₃ or CsPbI₃ by anion exchange, with preservation of the size and shape of the starting particles. The blue fluorescent CsPbCl₃ NPLs represent a new member of the scarcely populated group of blue-emitting colloidal nanocrystals. The exciton dynamics were found to be independent of the extent of 2D confinement in these platelets, and this was supported by band structure calculations.