Enhanced Photoluminescence and Random Lasing Emission in TiO₂-Decorated FAPbBr₃ Thin Films

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Organic-inorganic halide perovskites, particularly formamidinium lead bromide (FAPbBr3), are promising for optoelectrical applications.
• Controlling optical properties and enhancing light-matter interactions in perovskite thin films is crucial for device performance.

Purpose of the Study:

• To investigate the effect of titanium dioxide (TiO2) nanoparticle decoration on the optical properties of FAPbBr3 perovskite thin films.
• To explore the potential for enhanced photoluminescence and random lasing emission in TiO2-decorated FAPbBr3 films.

Main Methods:

• One-step spin-coating method for fabricating TiO2-decorated FAPbBr3 thin films.
• Optical characterization including absorption and photoluminescence spectroscopy.
• Confocal microscopy for analyzing light intensity redistribution and scattering phenomena.

Main Results:

• TiO2 nanoparticle decoration significantly alters the optical properties of FAPbBr3 films, reducing absorption and enhancing photoluminescence intensity.
• A blueshift in photoluminescence emission peaks was observed, attributed to variations in perovskite grain size.
• Random lasing emission with sharp peaks (FWHM 2.1 nm) was achieved, driven by light scattering within TiO2 nanoparticle clusters.

Conclusions:

• TiO2 decoration is an effective strategy to tune the optical properties of FAPbBr3 perovskite thin films.
• Multiple light scattering and coherent interactions within TiO2 clusters are key mechanisms for achieving random lasing.
• This research demonstrates potential for improving photoluminescence and random lasing efficiency in optoelectrical devices.