Decoration of MAPbI3 Perovskites with Carbon Dots for Enhanced Photoelectrochemical Performance and Stability

A composite of methylammonium lead iodide perovskite (MAPbI 3 ) and carbon dots is prepared under ultrasound irradiation. Characterizations of X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, emission field scanning electron microscopy, Raman spectra and UV-Vis diffuse reflectance spectroscopy are performed. Excellent photoelectrochemical properties of prepared composites are examined by a collection of measurements including photocurrent density, open-circuit potential, current–voltage curves, cyclic voltammetry curves and Nyquist plots. The results imply that the as-prepared composites exhibit better electrochemical and photoelectrochemical properties as well as stability than those of blank MAPbI 3 . The improved properties are due to the formed Pb–O–C bridge bonds in the composites, which can promote the generation and transport of charge carriers. This work provides a novel sonochemical synthesis strategy and investigation on the photoelectrochemical performance of MAPbI 3 /carbon dots composites.