Kinetics‐Controlled Interfacial Synthesis of Janus and Patchy Heterostructures Based on Perovskite Nanocrystals

Abstract

Heterostructures integrated by diverse material featuring nanocrystals (NCs) tunable properties and functions are of great interest. However, to rationally design and precisely control the heterostructures in multiple shapes still remains a tremendous challenge. In this work, the nucleation of SiO2 nanoparticles is manipulated via a kinetics‐controlled water–hexane interfacial reaction system to construct Cs3Cu2I5/SiO2 heterostructures, which can be well controlled in Janus and patchy morphology. In this interfacial reaction, the evolution of Cs3Cu2I5 NCs and the intrinsic formation mechanism of the heterostructures are investigated. It is observed that the Cs3Cu2I5 NCs on the interface undergo a morphology transformation driven by ligand loss and exposed facets evolution. Increased wettability between Cs3Cu2I5 and SiO2 favors the formation of Cs3Cu2I5/SiO2 heterostructures. The key to this strategy is to break the rule of thermodynamic domination in reaction by kinetics manipulation when constructing the patchy heterostructure. To be noted, an increased stability is conferred on the resultant heterostructure product compared to naked perovskite NCs. This work enables to better control the complicated heterostructure configurations and understand their formation mechanism.

A ligand strategy retarding monovalent copper oxidation toward achieving Cs3Cu2I5 perovskite emitters with enhanced stability for lighting

“…[27][28][29] For example, Zhao et al found that the luminescence of Cs 3 Cu 2 Cl 5 NCs cannot sustain under ambient atmosphere due to the oxidation of Cu + to Cu 2+ . 30 A similar situation was also observed in Cs 3 Cu 2 I 5 NCs 31 and Rb 2 CuBr 3 crystals. 32 Thus, suppressing the oxidation of monovalent copper ions is of great importance for maintaining the crystalline structure and luminescence properties.…”

Recent Advances and Opportunities of Eco‐Friendly Ternary Copper Halides: A New Superstar in Optoelectronic Applications

“…e–g) Reproduced with permission. [ 142 ] Copyright 2022, Wiley‐VCH. h) RL intensity of Cs 3 Cu 2 I 5 and Mn 2+ ‐doped Cs 3 Cu 2 I 5 at different temperature.…”

“…[210][211][212][213][214][215] Despite most TCH materials present enhanced stability compared to the lead-based perovskites, the stability issue of TCHs is still an ongoing challenge due to their ionic properties similar to perovskites. [140,142] Recently, many research groups have experimentally and theoretically studied the influence of environmental conditions on the structural and optical characters of TCHs, and many methods including surface passivation and ion doping, have been developed to surmount the stability troubles of TCHs. In this section, we will introduce the previous reports about the inherent stability of various TCHs, and critically review the key strategies to enhance the stability of TCHs.…”

“…PL intensity of f) water-treated Cs 3 Cu 2 I 5 NCs and g) Cs 3 Cu 2 I 5 /SiO 2 patchy NCs in five heating/cooling cycles. e-g) Reproduced with permission [142]. Copyright 2022, Wiley-VCH.…”

The synthesis of metal halide perovskite nanocrystals: surface and interface engineering

“…CsPbX 3 NCs could be formed at the water/hexane interface, which may provide an opportunity for nanoparticle surface modification. Prof. Zhang's group 102,103 demonstrated an effective sol–gel process for modifying the surface of perovskite NCs at the interface of water/nonpolar solvents and producing highly stable monodisperse CsPbX 3 /SiO 2 and CsPbBr 3 /Ta 2 O 5 Janus NCs, exhibiting significantly enhanced PL stability against damage by air, water, and light treatment. Additionally, the reaction rate could be controlled by changing the ions' interfacial diffusion rate in such a bi-phasic interface.…”