Unveiling the Ultrafast Electron Transfer Dynamics in Epitaxial Dodecahedron CsPbBr<sub>3</sub>/Au Heterostructure
Samaresh Samanta, K. Justice Babu, Ayushi Shukla, Gurpreet Kaur, Arshdeep Kaur, Hirendra N. Ghosh
Abstract
Abstract Epitaxial 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 CsPbBr 3 /Au heterostructure was synthesized via hot injection method. From HR‐TEM images, we observed direct epitaxial growth between (110) plane of CsPbBr 3 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 CsPbBr 3 /Au heterostructure, faster recovery has been noticed than that of pristine CsPbBr 3, which clearly suggests transfer of electrons from the conduction band of CsPbBr 3 to Au NPs. The distinct fast electron transfer in the CsPbBr 3 /Au heterostructure can be mainly ascribed to the epitaxial growth and strong electronic coupling between CsPbBr 3 and Au NPs. The reduced bleach intensity, faster bleach growth and recovery kinetics strongly suggest efficient electron transfer from CsPbBr 3 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.