A Facile Route to Cesium Lead Bromoiodide Perovskite Microcrystals and Their Potential Application as Sensors for Nitrophenol Explosives

Abstract

To achieve a material with pure phase and crystallinity, the use of antisolvents is found to be crucial. Herein, we report the synthesis of phase‐pure CsPbBr2I microcrystals with defined morphologies by using trioctylphosphine (TOP) as an antisolvent and capping agent. The as‐prepared inorganic perovskite has enhanced thermal stability and promising optical properties, displaying a band gap of 2.2 eV. The photoluminescence (PL) studies suggest high sensitivity of the as‐prepared inorganic perovskites against nitrophenols, which makes them a potential candidate for the detection of nitrophenol.

Porous Halide Perovskite–Polymer Nanocomposites for Explosive Detection with a High Sensitivity

“…The decay kinetics remain almost the same (with a time constant of about 0.25 ps) from sub‐picosecond to about 10 ps for all the samples. Given the fact that a charge transfer process typically occurs within this timescale, our result seems to oppose the charge transfer hypothesis in previous perovskite‐nitroaromatics PL quenching studies . On the other hand, adding TNT clearly accelerates the TA decay from about 100 ps to 6 ns, a time domain in which various trap states play an important role on exciton/charge carrier decay kinetics .…”

“…It is known that TNT is a good electron acceptor due to the strong electron withdrawing capability of the nitro functional groups. It has been hypothesized by others that there might be photoinduced charge transfer between perovskite and nitroaromatics . However, no evidence was presented in those works.…”

“…Their extraordinary optoelectronic properties and solution processability can potentially lead to large area and high‐performance devices at a low cost. In parallel, using halide perovskites for detecting various gases and chemical species has been studied including oxygen, ozone, acetone, ethanol, ammonia, and explosive nitroaromatics …”

“…Very recently, halide perovskites have also been studied as new alternative fluorophores. For instance, Aamir et al prepared cesium lead bromoiodide (CsPbBr 2 I) microcrystals in dimethylformamide (DMF) and demonstrated their use for detecting nitrophenol explosives . Muthu et al used methylammonium lead tribromide (MAPbBr 3 ) nanoparticles in toluene and reported their photoluminescence (PL) quenching characteristics by adding 2,4,6‐trinitrophenol …”

Extending Carrier Lifetimes in Lead Halide Perovskites with Alkali Metals by Passivating and Eliminating Halide Interstitial Defects

“…Hybrid organic-inorganic perovskites (HOIPs) are one of the most promising and widely studied types of new semiconductors.T hey have been the focus of intense recent attention owing to their remarkable photoelectric properties, including large charge carrier diffusion lengths, [1] long charge carrier lifetimes, [1] small exciton binding energies, [2] and high absorption coefficients. [3] Combined with simple synthetic procedures,t hese unique optoelectronic characteristics lead to diverse applications in photoelectric devices,s uch as sensors, [4] light-emitting diodes, [5] photocatalytic water-splitting assemblies, [6] and solar cells. [7] In particular,t he power conversion efficiency of HOIP solar cells has rapidly increased from 3.8 % [8] to 25.2 % [9] in recent years,close to that of single-crystalline silicon solar cells.…”