Large scale quantum dynamics investigations on the sensing mechanism of H2O, acetone, NO2 and O3 adsorption on the (MA)2Pb(SCN)2I2 surface

Sensing Mechanism of H2O, NH3, and O2 on the Stability-Improved Cs2Pb(SCN)2Br2 Surface: A Quantum Dynamics Investigation

Although the perovskite sensing materials have shown high sensitivity and ideal selectivity toward neutral, oxidative, or reductive gases, their structural instability hampers the practical application. To exploit perovskite-based gas-sensing materials with improved stability and decent sensitivity, three adsorption complexes of H2O, NH3, and O2 on the Cs2Pb(SCN)2Br2 surface are built by doping Br- and Cs+ in the parent (CH3NH3)2Pb(SCN)2I2 structure and submitted to quantum dynamics simulations. Changes in the semiconductor material geometric structures during these dynamic processes are analyzed and adsorption ability and charge transfer between Cs2Pb(SCN)2Br2 and the gas molecules are explored so as to further establish a correlation between the geometrical structure variations and the charge transfer. By comparing with the previous CH3NH3PbI3 and (CH3NH3)2Pb(SCN)2I2 adsorption systems, we propose the key factors that enhance the stability of perovskite structures in different atmospheres. The current work is expected to provide clues for developing innovative perovskite sensing materials or for constructing reasonable sensing mechanisms.

Review on Sensing Applications of Perovskite Nanomaterials

Recently, perovskite-based nanomaterials are utilized in diverse sustainable applications. Their unique structural characteristics allow researchers to explore functionalities towards diverse directions, such as solar cells, light emitting devices, transistors, sensors, etc. Many perovskite nanomaterial-based devices have been demonstrated with extraordinary sensing performance to various chemical and biological species in both solid and solution states. In particular, perovskite nanomaterials are capable of detecting small molecules such as O2, NO2, CO2, etc. This review elaborates the sensing applications of those perovskite materials with diverse cations, dopants and composites. Moreover, the underlying mechanisms and electron transport properties, which are important for understanding those sensor performances, will be discussed. Their synthetic tactics, structural information, modifications and real time sensing applications are provided to promote such perovskite nanomaterials-based molecular designs. Lastly, we summarize the perspectives and provide feasible guidelines for future developing of novel perovskite nanostructure-based chemo- and biosensors with real time demonstration.