2D Materials Beyond Graphene for Metal Halide Perovskite Solar Cells

Abstract

In this Research News, the authors summarize the work that has been done on the utilization of 2D materials beyond graphene in the electron transport layer (ETL) and hole transport layer (HTL) selected of metal halide perovskite solar cells (PSCs). On the one hand, the impact of such materials in the stability of PSCs under operational conditions is impressive. Stabilities for encapsulated PSCs cells under illumination and ambient conditions at maximum power point that retain 80% of their initial performance (T80) have been reported. On the other hand, the extraction of photogenerated holes has been reduced to few microsecond when a 2D material–based HTL or ETL is introduced. The faster photogenerated charge extraction lowered the recombination rates and resulted in higher power conversion efficiencies. The most interesting thing is that the 2D materials have been successfully applied for large active area cells (≈1.05 cm2) as well. The exploitation of 2D materials, beyond graphene, is a very interesting and promising technology that shows a high potential pathway towards the envisioned future commercialization of PSCs through addressing their performance, stability, and scalability priorities.

Recent Advances in 2D Metal Monochalcogenides

“…In such devices, 2D materials are widely used as in the active (donor) or in various interface/interconnecting layers for exciton generation or charge extraction. [196][197][198][199][200][201][202][203][204] A promising novel donor material should have direct bandgap (1.2-1.6 eV), high absorption coefficient, high carrier mobility, and low exciton binding energy, E B . A low E B is favorable for the efficient separation of photogenerated charge carriers.…”

SnO2–Ti3C2 MXene electron transport layers for perovskite solar cells

“…[17][18][19] In recent years, two-dimensional (2D) materials, especially graphene, have attracted great attention and have been used in PSCs due to their unique optical and electronic properties. 20,21 To date, CH3NH3PbI3-based regular (n-i-p type) and inverted (p-i-n type) PSC containing graphene oxide (GO) as charge transport layer were reported to achieve PCEs of 18.19% 22 and 13.8% 23 , respectively. Reducing GO has proven an effective method to improve the conductivity of GO and Yeo et al reported the first reduced graphene oxide (rGO)-based inverted CH3NH3PbI3 PSC, which reached a PCE of 10.8%.…”

A two-fold engineering approach based on Bi2Te3 flakes towards efficient and stable inverted perovskite solar cells

“…The incorporation of two-dimensional (2D) materials at different sections of perovskite solar cells (PSCs) represents an effective approach to enhance both the power conversion efficiency (PCE) and the lifetime stability of such photovoltaic technology. [1][2][3][4] Meanwhile, the exceptional optoelectronic properties of 2D materials and their compatibility with large-scale, solutionprocessable methods (e.g., roll-to-roll printing techniques) lay the ground for the direct integration of low-cost and flexible photovoltaic devices in emerging smart and multifunctional technologies. [5][6][7][8][9][10][11] The beneficial impact of graphene and related 2D materials in PSCs has been demonstrated both in mesoporous [12][13][14][15][16] and inverted planar structures, [17][18][19] as well as in their corresponding tandem systems.…”