Achieving direct electrophoretically deposited highly stable polymer induced CsPbBr3 colloidal nanocrystal films for high-performance optoelectronics

Abstract

Synthesizing colloidal nanocrystals (NCs) with long-term stable under ambient conditions via appropriate ligands capping is highly challenging. Herein, the rapid synthesis of CsPbBr3 colloidal NCs at room temperature using polyvinylpyrrolidone as the primary ligand is demonstrated. The addition of ethylene glycol stabilizes the colloidal NCs and enhance their photoluminescence by ~ 5-fold. Colloidal NCs have a net negative surface charge, which enables the direct electrophoretic deposition of a polymer-induced all-inorganic CsPbBr3 NC film with ultra-high stability under ambient conditions at relative humidity of 55% for 240 days. As an example of the application of the CsPbBr3 NC film in an optoelectronic device, a hybrid MoS2/CsPbBr3 field-effect phototransistor is fabricated, which exhibits a detectivity of 9 x 10(12) Jones and an ultra-high responsivity of 1.2 x 10(7) A W-1 under the illumination of 450-nm laser at 4.4 pW. The noble and practical methods applied in our CsPbBr3 NC films could be extended to produce various types of uniform NC films over a large geometrical area with outstanding long-term environmental stability, holding significant promise for use in a broad range of advanced optoelectronic devices.