Heavy Mn-doped CsPbBr₃ nanocrystals synthesized by high energy ball milling with high stability

Abstract

CsPbX3 (X=Cl, Br, I) semiconductor nanocrystals (NCs) have excellent optical and photoelectric properties, and are potential core materials for various photoelectric devices. However, the toxicity of Pb and instability have been the key limitations to application of NCs. Herein, using MnBr2 and MnBr2·4H2O as manganese sources, heavy Mn-doped CsPbBr3 (Mn:CsPbBr3) NCs are synthesized by high-energy ball grinding, which avoids high temperature, a large number of polar solvents and atmosphere protection required in traditional liquid phase methods. However, when MnBr2·4H2O is used as the raw material, infinite solid solution doping can be achieved, and the synthesized Mn:CsPbBr3 NCs show stronger PL intensity and stability. The reason is that presence of crystal water plays a similar role to wet milling in the ball milling process, and can promote the passivation effect of oleylamine (OAm) on nanocrystal defects and the connection between them. In addition, a simple, low-cost, easy to operate and beneficial to commercial production method for the preparation of Mn:CsPbBr3 NCs/EVA flexible films is proposed, which can effectively improve the stability of Mn:CsPbBr3 NCs. This study is expected to provide an effective way for the synthesis and stability improvement of CsPbX3 NCs doped with different ions.

Solution-grown millimeter-scale Mn-doped CsPbBr3/Cs4PbBr6 crystals with enhanced photoluminescence and stability for light-emitting applications

“…The PL peak of the CsPbBr 3 / Cs 4 PbBr 6 :Mn 2+ crystals is blue-shifted by about 7 nm compared with the as-grown CsPbBr 3 /Cs 4 PbBr 6 crystals, without showing a new PL peak. This phenomenon is contradictory to that of the Mn 2+ -doped CsPbBr 3 system with a higher content of Mn 2+ doping, 41 while exhibiting a similar blue-shifted PL peak with lower content of Mn 2+ doping. 31,41 As described in Fig.…”

“…This phenomenon is contradictory to that of the Mn 2+ -doped CsPbBr 3 system with a higher content of Mn 2+ doping, 41 while exhibiting a similar blue-shifted PL peak with lower content of Mn 2+ doping. 31,41 As described in Fig. 2a-c, for the as-grown CsPbBr 3 /Cs 4 PbBr 6 crystals, the green PL emission comes from the CsPbBr 3 phase.…”

“…The improved PL performance from doping the Mn 2+ ions into the CsPbBr 3 /Cs 4 PbBr 6 crystals may be attributed to Mn 2+ possibly passivating the surface or grain boundary defects of the Mn-doped CsPbBr 3 /Cs 4 PbBr 6 crystals. 41,42 To further confirm the success of Mn 2+ doping, the crystal was characterized using powder XRD measurement. The comparison of the powder XRD spectroscopy of the CsPbBr 3 /Cs 4 PbBr 6 and CsPbBr 3 /Cs 4 PbBr 6 :Mn 2+ crystals are shown in Fig.…”

Inorganic Salt Solution Assisted Grinding Synthesis of Stimuli-Responsive Perovskites for Reversible Information Encryption and Decryption Based on I Ching 64 Hexagrams

“…Moreover, grinding collisions reduce the material granularity, increasing the reactants’ surface area. The pressure and heat generated during grinding facilitate ion migration and exchange, − accelerating the formation of target products. As shown in step 2 of Figure a, with the addition of KCl solution (eq , KCl is ionized in water) and subsequent heating treatment, hydrone from the solution evaporates, gradually releasing K + and Cl – ions and elevating the reactants concentration of reaction eq .…”