Recombination dynamics in CsPbBr_3 nanocrystals: role of surface states

Abstract

We present a detailed experimental investigation of the carrier recombination dynamics in CsPbBr 3 films by means of picosecond time-resolved photoluminescence. Temperaturedependent measurements show that carrier capture and release from the nanocrystals (NCs) surfaces determine the observed increase of the recombination lifetime with the increase of temperature. This result opens the way to probe the surface of the NCs, which is of the utmost relevance for optoelectronic applications, and to eventually give feedback for surface treatments of NCs.

Long-living nonlinear behavior in CsPbBr3 carrier recombination dynamics

“…Persistent energetic electrons have been already observed in MAPbI 3 [35] and FAPbI 3 [41] and a reduced density of states has recently been proposed as the origin of the slow dynamics and cooling in CsPbI 3 [42]. We recently demonstrated [43], for SC samples, that surface states can efficiently trap the carriers, with a long release time, providing a carrier reservoir for the radiative recombination: therefore, surface states can play a role in the thermalization process and similarly in bulk high energy long-living traps eventually related to small structural defects or inclusions (e.g. CsPbBr 5 , or PbBr 2 ).…”

Defective States in Micro-Crystalline CsPbBr3 and Their Role on Photoconductivity

“…After thermal annealing at 150 °C, a dense and continuum layer of interconnected CsPbBr 3 microcrystals of the order of a few μms was manufactured. The film has been then covered with polymethylmethacrylate (PMMA) to prevent deterioration due to air and water vapor [ 23 ]. XRD ( Figure 1 b) and XPS analyses demonstrated the good quality of the film with no residual solvent and contaminants.…”

First Proof-of-Principle of Inorganic Lead Halide Perovskites Deposition by Magnetron-Sputtering

“…Among the materials proposed for optoelectronic devices, halide perovskite materials present several advantages such as the relatively low-cost, the possibility to tune the band gap varying the composition, and the different kind of nanostructure obtainable. For such reasons, halide perovskites have been recently proposed as novel materials for solar cells, sensors and LEDs [3,[6][7][8][9][10].…”