Fig. 1. (Color online) (a) Surface-treating and anion-exchange process of CsPbBr₃ PNCs by using OAm-I or An-HI. Reproduced with permission^[26], Copyright 2018, Nature Publishing Group. (b) Schematic for PNC-LED with bilateral passivation and the corresponding sectional TEM image. Reproduced with permission^[31], Copyright 2020, Nature Publishing Group. (c) Treating PNCs with glutathione and EDTA to remove excess surface Pb²⁺. Reproduced with permission^[34], Copyright 2021, Nature Publishing Group.

Fig. 2. (Color online) (a) Schematic for GA⁺-doped FAPbBr₃ PNCs. (b) EQE–V curves for LEDs based on GA⁺-doped FAPbBr₃ PNCs with different GA⁺ doping content. (a, b) Reproduced with permission^[9], Copyright 2021, Nature Publishing Group. (c) Energy level diagram showing the change in the energy band of Zn²⁺-doped CsPbI₃ PNCs. (d)J–V–L curves for LEDs based on CsPbI₃ and Zn²⁺-doped CsPbI₃ PNCs. Insets show the working LEDs. (c, d) Reproduced with permission^[40], Copyright 2019, American Chemical Society. (e) Energy transfer in Mn²⁺-doped nanocrystal. Reproduced with permission^[36], Copyright 2018, Elsevier.