First-Principles Study of Group VA Monolayer Passivators for Perovskite Solar Cells

Abstract

With the increasing energy demands, the production of high-performance perovskite solar cells at economic cost is favorable. However, there are limitations to their commercial applications due to defect formation and instability. Passivation technologies help support their desirable traits. Recently, experiments have proven nanoscale group VA monolayers to be good passivator candidates. Simulated by these recent results, we applied density functional theory to systematically investigate the structural, electronic, optical, and mechanical properties of α and β phases of group VA monolayers, including phosphorene, arsenene, antimonene, and bismuthene in this project. The theoretical results reveal the following: (1) α-phosphorene and β-arsenene have ideal valence band maximum locations, while all monolayers have ideal conduction band minimum locations for enhancing open-circuit potential; (2) most monolayers have light effective masses for improving short-circuit current densities; (3) the location of passivators is important due to their high absorption coefficients; and (4) α-arsenene, α-bismuthene, and α-antimonene are ductile, which can potentially be used in flexible solar cells. Overall, theoretical insights suggest that α-phosphorene and both α- and β-arsenene are promising passivators with the consideration of all the electronic, optical, and mechanical properties.

Theoretical investigation of the effect of mole fraction on the electronic and optical properties of a binary armchair antimonene−phosphorene nanoribbon

“…Absorption coefficient curve shows that pristine Sb nanoribbon possesses an absorption peak at 3.3 eV, and its peak value is 4.62 × 10 5 cm −1 , which is in good agreement with the theoretical value of 4.59 × 10 5 cm −1 , also [66]. For phosphorene nanoribbon, the value of absorption coefficient at 4 eV is equal to 4.55 × 10 5 cm −1 , which is close to the theoretical work reported on phosphorene monolayer in β-phase with a value of 4.58 × 10 5 cm −1 [67]. From the theoretical point of view, in 2018, the optical properties of antimonenephosphorene monolayer in β-phase were investigated using density functional theory, and their results showed that this monolayer has absorption in the visible region with an energy of 2.8 eV and value of 1.2 × 10 5 cm −1 [29], which is comparable to our results with an absorption value of 1.3 × 10 5 cm −1 .…”

Halogenation effect on physicochemical properties of Ti3C2 MXenes

“…The more negative cohesive energy value suggests a higher stability. The calculated cohesive energies of all the halogenated MXenes are lower than that of some stable 2D materials, including silicene (−4.57 eV) [40], α-phosphorene (−3.58 eV) and β-phosphorene (−3.56 eV) [41]. It indicates that all the Ti 3 C 2 T 2 considered here are stable.…”

A theoretical review of passivation technologies in perovskite solar cells

“…Experimental results showed a modest increase in J SC from 22.21 to 23.32 mA/cm 2 after introducing phosphorene passivators. The effectiveness of using black phosphorene as a passivator to improve J SC has also been experimentally confirmed by Macdonald et al [94] .…”