Blue light irradiation-stirred washing high luminescence and highly stable CsPbBrI2 quantum dots modified with CaO for backlight display

Perovskite quantum dots (QDs) have become the star material for liquid crystal display (LCD). However, instability affects its practical application. Herein, CsPbBrI 2 quantum dots (CsPbBrI 2 QDs) with high quantum efficiency have been successfully precipitated in situ by adding CaO to the Li-Al-Si glass substrate. The photoluminescence quantum yield (PLQY) was adjusted from 64.5 % to 87.5 %. At the same time, we adopted a new strategy of blue light irradiation-stirred water washing. When blue light irradiation and stirred water washing interact synergistically, the naked CsPbBrI 2 QDs detached from the glass surface, while smaller CsPbBrI 2 QDs continued to grow. This process successfully resulted in CsPbBrI 2 QDs with high luminescence intensity and high stability. Moreover, when exposed to 60 °C, 90 % relative humidity (RH), and 2000 nit blue light for 240 hours (h), the treated sample could retain 91.1 % of the original emission intensity. The color gamut of the prepared CsPbBrI 2 @CsPbBr 3 @glass@polystyrene (PS) light conversion film covered 122 % of the NTSC 1953 standard and 90 % of the Rec. 2020 standard. It provided great value for the commercialization of QDs in backlight display applications.