A Review on Interface Engineering of MXenes for Perovskite Solar Cells

Abstract

With an excellent power conversion efficiency of 25.7%, closer to the Shockley–Queisser limit, perovskite solar cells (PSCs) have become a strong candidate for a next-generation energy harvester. However, the lack of stability and reliability in PSCs remained challenging for commercialization. Strategies, such as interfacial and structural engineering, have a more critical influence on enhanced performance. MXenes, two-dimensional materials, have emerged as promising materials in solar cell applications due to their metallic electrical conductivity, high carrier mobility, excellent optical transparency, wide tunable work function, and superior mechanical properties. Owing to different choices of transition elements and surface-terminating functional groups, MXenes possess the feature of tuning the work function, which is an essential metric for band energy alignment between the absorber layer and the charge transport layers for charge carrier extraction and collection in PSCs. Furthermore, adopting MXenes to their respective components helps reduce the interfacial recombination resistance and provides smooth charge transfer paths, leading to enhanced conductivity and operational stability of PSCs. This review paper aims to provide an overview of the applications of MXenes as components, classified according to their roles as additives (into the perovskite absorber layer, charge transport layers, and electrodes) and themselves alone or as interfacial layers, and their significant importance in PSCs in terms of device performance and stability. Lastly, we discuss the present research status and future directions toward its use in PSCs.

Surface pre-sacrifice behavior of thiourea-based 2D perovskites for high-performance perovskite solar cells

“…[10][11][12][13][14][15] Interface modification strategies are currently one of the most widely studied and effective methods to reduce the defect density inside the PSCs. 16,17 Various types of passivating molecules with different chemical structures have been designed to target different types of defects at the interface, such as 4hydroxypicolinic acid (4HPA), 18 N-(2-pyridyl)pivalamide (NPP), 19 self-crosslinked fluorosilicone polymer gel, 20 octylamine (OA) functionalized with sulfanilic acid (OAS), p-toluenesulfonic acid (OAT), camphorsulfonic acid (OAC), 21 and so on. However, due to the singularity of organic passivation molecules, improvements in both efficiency and stability remain limited.…”

Polynary energy harvesting and multi-parameter sensing in the heatwave environment of industrial factory buildings by an integrated triboelectric–thermoelectric hybrid generator

“…Solar cells based on the photovoltaic effect can effectively convert light energy into electricity, which is one of the most promising energy harvesting technologies. 7,8 During the falling process, a raindrop can be triboelectrically charged due to contact with air and some micro-particles (the charge polarity is dependent on the object that the raindrop is in contact with), thus possessing electrostatic energy. In addition, the transformation of gravitational potential energy into kinetic energy endows raindrops with certain momentum.…”

Healing the Buried Interface by a Plant-Derived Green Passivator for Carbon-Based CsPbIBr2 Perovskite Solar Cells

“…Organic–inorganic hybrid perovskite solar cells (PSCs) have attracted extensive attention due to their unique semiconductor properties, such as long charge carrier diffusion length, tunable bandgap, high defect tolerance, and low exciton binding energies. − Within a very short time span, impressive achievements in photovoltaic applications have been made, and the certificated power conversion efficiency (PCE) of single-junction PSCs has been rapidly increased to 26.1%, which is comparable to that of Si-based solar cells. − However, the poor long-term operational stability still restricts their practical application, largely because of the usage of humidity-/heat-sensitive organic methylammonium and formamidinium. − Substituting organic cations with volatile-free Cs + to fabricate all-inorganic perovskites (CsPbX 3 , X = I, Br, Cl, or mixed) is an effective strategy to settle this issue. , Generally, there is a positive correlation between I doge and corresponding PCE owing to the reduced bandgap but a negative relationship for environmental stability. Although the efficiency of CsPbI 3 -based PSCs has exceeded 20%, the phase instability, which suffers from the phase conversion from the photoactive α-perovskite phase to the nonphotoactive β-perovskite phase, is still a great challenge for future deployment. ,, On the contrary, CsPbBr 3 exhibits the most superior stability, but its PCE is restricted by a narrower light-absorbing range .…”