Unveiling the Ultrafast Electron Transfer Dynamics in Epitaxial Dodecahedron CsPbBr3/Au Heterostructure

Abstract

AbstractEpitaxial perovskite heterostructures consisting noble metal nanoparticles have been received immense interest in hot carrier photovoltaic devices and photocatalysis. The major understanding of carrier extraction across the interface of perovskite heterostructure have shown exciting interest for next generation device applications. In the present study, dodecahedron CsPbBr3/Au heterostructure was synthesized via hot injection method. From HR‐TEM images, we observed direct epitaxial growth between (110) plane of CsPbBr3 and (111) plane of Au nanoparticle (NPs), which was further supported by steady‐state and time‐resolved photoluminescence studies. Further, femtosecond transient absorption spectroscopy has been utilized to understand the charge transfer dynamics of synthesized samples. In CsPbBr3/Au heterostructure, faster recovery has been noticed than that of pristine CsPbBr3, which clearly suggests transfer of electrons from the conduction band of CsPbBr3 to Au NPs. The distinct fast electron transfer in the CsPbBr3/Au heterostructure can be mainly ascribed to the epitaxial growth and strong electronic coupling between CsPbBr3 and Au NPs. The reduced bleach intensity, faster bleach growth and recovery kinetics strongly suggest efficient electron transfer from CsPbBr3 NCs to Au NPs. These findings clearly establish that architecture of metal and perovskite heterostructures may pave way to develop suitable alternative for highly efficient photovoltaic devices and photocatalysis applications.