Double epitaxial growth of ultra-stable Ga2O3/CsPbBr3/CsGaSi2O6 heterostructure for multimodal applications

Abstract

Constructing multicomponent heterostructures of lead halide perovskite nanocrystals is crucial for achieving highly stable and enhanced photoluminescence, as well as expanding optoelectronic applications. Herein, a MCM-41 molecular sieves induced double epitaxial growth strategy is proposed to construct ternary Ga2O3/CsPbBr3/CsGaSi2O6 heterostructure. MCM-41 molecular sieves inhibit the decomposition of CsPbBr3 nanocrystals (NCs) during the heating process and serve as a silicon source to generate another lattice matched CsGaSi2O6 while CsPbBr3 NCs epitaxially grow on Ga2O3. Based on lattice-matched epitaxial growth of Ga2O3 and CsGaSi2O6 on CsPbBr3, the Ga2O3/CsPbBr3/CsGaSi2O6 heterostructure exhibits significantly enhanced photoluminescence and the maximum photoluminescence quantum efficiency is 47.9%. Due to the dual surface defect passivation of Ga2O3 and CsGaSi2O6, the heterostructure exhibits high stability against ultraviolet (UV) irradiation, water, and heat. Based on the excellent stability and bright luminescence of heterostructures, high-sensitivity temperature sensing with a maximum relative temperature sensitivity (Sr) of 6.4% at 363 K and fingerprint recognition have been achieved. Meanwhile, WLEDs equipped with the heterostructure reached a high luminous efficiency of 68.4 lm. W-1. This work provides a simple and green approach in assembling lattice matched multicomponent perovskite heterostructures with enhanced photoluminescence and stability for multimodal applications.