An inherent instability study using ab initio computational methods and experimental validation of Pb(SCN)2 based perovskites for solar cell applications

Abstract

Perovskite materials with ABX3 chemistries are promising candidates for photovoltaic applications, owing to their suitable optoelectronic properties. However, they are highly hydrophilic and unstable in nature, limiting the commercialization of perovskite photovoltaics. Mixed halide ion-doped perovskites are reported to be more stable compared to simple ABX3 chemistries. This paper describes ab initio modeling, synthesis, and characterization of thiocyanate doped lead iodide CH3NH3PbI(3−x)(SCN)x perovskites. Several perovskite chemistries with an increasing concentration of (SCN)− at x = 0, 0.25, 0.49, 1.0, 1.45 were evaluated. Subsequently, ‘n-i-p’ and ‘p-i-n’ perovskite solar device architectures, corresponding to x = 0, 0.25, 0.49, 1.0 thiocyanate doped lead halide perovskite chemistry were fabricated. The study shows that among all the devices fabricated for different compositions of perovskites, p-i-n perovskite solar cell fabricated using CH3NH3PbI(3−x)(SCN)x perovskite at x = 1.0 exhibited the highest stability and device efficiency was retained until 450 h. Finally, a solar panel was fabricated and its stability was monitored.

Growth Kinetics and Optical Properties of CsPbBr3 Perovskite Nanocrystals

“…The absorption coefficient (α), which is directly proportional to the optical density and incident photon energy (hυ), can be used to determine the optical bandgap by extrapolating the straight-line portion of the plot of the quantity (αhυ) 2 vs. photon energy [22]. The authors of a previous study reported that the calculated bandgap of perovskite materials from the Tauc plot compares with the discrete Fourier transform computed bandgaps [23]. In addition, the bandgap can be estimated using the Tauc plot without considering the exciton binding energy, and the results were in good agreement with the energy levels (conduction/valence band) derived from the photoelectron spectroscopy measurement [24].…”

Quasi-Type II Core–Shell Perovskite Nanocrystals for Improved Structural Stability and Optical Gain

“…Lead halide perovskite nanocrystals (PeNCs) have become a promising candidate in the field of optoelectronics owing to their large optical absorption coefficient (10 4 –10 5 cm –1 ), tunable band gap, narrow emission bandwidth, and high photoluminescence quantum yield (PLQY). − The power conversion efficiency (PCE) of the monolithic perovskite/silicon tandem solar cell has already reached 29.15% within a very short period . Meanwhile, multicolor light-emitting diodes (LEDs) and low threshold optical-pumped lasers have been realized with excellent performance. , However, the ionic nature of PeNCs results in a significant drawback of high environmental sensitivity, which limits their practical applications. , Furthermore, up to now, studies have shown that high-temperature, oxygen, moisture, ultraviolet (UV) light exposure, and structural transformation lead to the decomposition of perovskite materials and degrade the device stability. − Therefore, progress in improving the stability of the material without sacrificing its performance is crucial for the development of PeNCs in the future.…”

“…7,8 However, the ionic nature of PeNCs results in a significant drawback of high environmental sensitivity, which limits their practical applications. 9,10 Furthermore, up to now, studies have shown that high-temperature, oxygen, moisture, ultraviolet (UV) light exposure, and structural transformation lead to the decomposition of perovskite materials and degrade the device stability. 11−15 Therefore, progress in improving the stability of the material without sacrificing its performance is crucial for the development of PeNCs in the future.…”

Passivation of Surface Defects by X-type Short-Chain Ligands for High Quantum Yield and Stable CsPbX3 Quantum Dots Synthesis and Application in WLEDs

“…38 Some scholars have also compared the tauc map data of perovskite materials with the simulation results of band gap simulation by discrete Fourier transform, and the results are very consistent. 39,40 From the tauc plot results, it can be seen that with the increase of ligand concentration, the energy gap also increases. It is speculated that the increase of ligand inhibits the growth of quantum dots, affects its size, and causes the change of energy gap.…”