Improving the Stability of CsPbBr3 Perovskite Nanocrystals by Peroxides Post-treatment

Abstract

Metal oxides exhibit excellent barrier properties against moisture and oxygen, which are regarded as the powerful candidate for boosting the stability of perovskite nanocrystals (NCs). Here, we develop a simple method to coat perovskite NCs with PbO by peroxides post-treatment. Firstly, the didodecyl dimethyl ammonium sulfide (DDAS) was used to modify the CsPbBr 3 NCs (DDAS-CsPbBr 3 ), and then sequentially treated with benzoyl peroxide (BPO). By this way, the self-metal source (lead) can be easily oxidized, leading to the quick growth of lead oxide (PbO) on the surface of individual CsPbBr 3 NCs. Under illumination with a 450 nm LED light (175 mW/cm 2 ), the PbO coated CsPbBr 3 NCs maintained at ∼90% of the initial intensity for 20 h of operations; in contrast, the emission from the CsPbBr 3 NCs completely quenched.

Surface Passivation Strategies for Improving Photoluminescence and Stability of Cesium Lead Halide Perovskite Nanocrystals

“…The PL property of such modified-NCs was maintained 90% for 20 hours under continuous illumination with 450 nm LED light. [81] Achieving the thermodynamic stability of colloidal NCs under different ranges of concentrations has an upsurging demand for practical applications. This was achieved by using a long-chain zwitterionic phospholipid, soy-lecithin which can be mass-produced and less expensive.…”

“…They also used (S 2− ‐DDA + ) for modifying CsPbBr 3 NCs and then sequentially treated them with benzoyl peroxide to initiate the oxidation of the self‐metal source, forming PbO. The PL property of such modified‐ NCs was maintained 90% for 20 hours under continuous illumination with 450 nm LED light [81] . Achieving the thermodynamic stability of colloidal NCs under different ranges of concentrations has an upsurging demand for practical applications.…”

The Stability of Metal Halide Perovskite Nanocrystals—A Key Issue for the Application on Quantum-Dot-Based Micro Light-Emitting Diodes Display

“…Due to the local electric field induced by the trapped charge along the grain boundary, reducing the defects in the perovskite is considered to be an effective way to improve its optical stability. Liu et al used lead oxide to coat MHP-NCs through peroxide post-treatment [ 68 ]. First, CsPbBr 3 NCs (DDAS-CsPbBr 3 ) was modified with dodecyl dimethylammonium sulfide (DDAS), and then benzoyl peroxide (BPO) was used in turn.…”

“…( B ) Photostability of the different BPO oxidized DDAS–CsPbBr 3 NCs (0.050 mmol DDAS treatment). Reproduced from [ 68 ].…”

Surface Functionalization of CsPbBr3 Νanocrystals for Photonic Applications

“…In reality, surface chemistry plays a key role in tackling a major deficiency of such NCs related to the softness of the material and the dynamic nature of ligand binding, which renders LHP NCs colloidally and structurally unstable. Various synthesis methods, summarized into three main strategies, have been employed to circumvent such lability: (i) the addition of new ligand complexes; − (ii) the application of postsynthetic, passivation treatment; − and (iii) the incorporation into various host matrices. − Among the most successful and practical approaches, a combination of the ligand and postsynthetic passivation strategies was implemented to produce robust CsPbBr 3 NCs with near-unity emission quantum yields (QYs), for instance, using didodecyldimethylammonium bromide (DDAB) complexes ,, and long-chain zwitterionic (ZI) ligands . The simplicity and the highly successful outcome of the two treatments make them a highly promising surface-functionalization protocol for producing stable and bright CsPbBr 3 NCs for applications and devices.…”