Recently, semiconductor heterostructures
comprising mixed-dimensional
materials have attracted widespread attention due to their application
in catalysis, photovoltaics, and optoelectronics. Here, we report
the nano-heterostructure integration of CsPbBr3 nanocrystals
(NCs) and ultrathin nanosheets (NSs) of Bi2O2Se to explore their optical properties. The formation of heterostructures
was verified from the powder X-ray diffraction (PXRD) pattern and
transmission electron microscopy (TEM) analysis, whereas the bonding
interactions were studied using Fourier transform infrared (FTIR)
spectroscopy. The photoluminescence (PL) quenching of CsPbBr3 NCs in the mixed-dimensional CsPbBr3@Bi2O2Se heterostructure was evidenced both at 298 and 77 K. Time-resolved
PL was implemented to examine the charge transfer characteristics
in these mixed-dimensional nano-heterostructures at both temperatures.
PL quenching appeared as a result of the charge transfer from the
conduction band of CsPbBr3 to Bi2O2Se via type-I electronic band alignment. The rate
of charge transfer across the heterojunction was found to be relatively
faster at 298 K than at 77 K.