A Brief Review of the Role of 2D Mxene Nanosheets toward Solar Cells Efficiency Improvement

Abstract

This article discusses the application of two-dimensional metal MXenes in solar cells (SCs), which has attracted a lot of interest due to their outstanding transparency, metallic electrical conductivity, and mechanical characteristics. In addition, some application examples of MXenes as an electrode, additive, and electron/hole transport layer in perovskite solar cells are described individually, with essential research issues highlighted. Firstly, it is imperative to comprehend the conversion efficiency of solar cells and the difficulties of effectively incorporating metal MXenes into the building blocks of solar cells to improve stability and operational performance. Based on the analysis of new articles, several ideas have been generated to advance the exploration of the potential of MXene in SCs. In addition, research into other relevant MXene suitable in perovskite solar cells (PSCs) is required to enhance the relevant work. Therefore, we identify new perspectives to achieve solar cell power conversion efficiency with an excellent quality-cost ratio.

Keywords: HTL/ETL; MXenes; additives; electrodes; power conversion efficiency; solar cells.

Figure 1

MXene synthesis, properties, and their applications. Reprinted with permission from ref. [73]. Copyright 2021 John Wiley & Sons, Inc.

Figure 2

Mechanism diagram for the production of high-quality perovskite films processed in two steps, supported by the additive Ti₃C₂T_x. Reprinted with permission from ref. [100]. Copyright 2020 Elsevier B.V.

Figure 3

Schematic representation of the IPSCs configuration. Reprinted with permission from ref. [102]. Copyright 2020 Elsevier B.V.

Figure 4

(a) Chemical structures of PBDB-T and ITIC. (b) Band diagram of the materials used in IPSCs. Reprinted with permission from ref. [102]. Copyright 2020 Elsevier B.V.

Figure 5

(a) Schematic representation of devices with the structure glass/ITO/SnO₂/2D perovskite/SpiroOMeTAD/Ag. (b) JV curves from devices with different amounts of Ti3C2Tx doping. (c) EQE spectra and integrated Jsc of the control and optimised Ti₃C₂T_x doping devices. (d) Stabilised power output and current density at a constant bias 0.80 V for the Ti₃C₂T_x dopant devices. Reprinted with permission from ref. [99]. Copyright 2021 Springer Nature Switzerland AG. Part of Springer Nature.

Figure 6

(a) Schematic representation of the MXene/AgNW hybrid electrodes on PUA substrates. (b) AFM images of the MXene/AgNW PUA films. (c) Transmission spectra of pure PUA, MXene-PUA, Ag NW-PUA, optimised MXene/Ag NW-PUA, and ITO glass. (d) Energy level diagrams of the flexible OSCs. (e) JV curves of the flexible OSCs with PBDB-T: ITIC: PC71BM active layers. (f) Normalised PCE of the flexible OSCs with MXene/Ag NW electrodes as a function of the number of bending cycles. Reproduced with permission. Reprinted with permission from ref. [116,117]. Copyright 2019 American Chemical Society.

Figure 7

Schematic representation of an experimental procedure. Reprinted with permission from ref. [118]. Copyright 2021 Elsevier Ltd. and Techna Group S.r.l.

Figure 8

(a) Device architecture of the prepared ITO/HTL/CH₃NH₃PbI₃/PCBM/LiF/Al prototype using Mo₂C-CNTs @ PEDOT: PSS HTL and (b) FESEM cross-sectional image; (c) Energy level diagram for ITO/Mo₂C-CNTs @ PEDOT: PSS/CH₃NH₃PbI₃/PCBM/LiF/Al structure. Reprinted with permission from ref. [121]. Copyright 2021 Elsevier B.V.

Figure 9

Schematic representation of the manufacturing processes of the perovskite film and the ETL. Reprinted with permission from ref. [123]. Copyright 2021American Chemical Society.

Figure 10

(a) The schematic diagram of the device structure and the structure of Nb₂CT_x MXene. (b) JV curves of PVSCs measured under different scan directions. (c) External quantum efficiency (EQE) and integrated Jsc curves of various PVSCs. JV curves of the flexible (d) and large-area (e) PVSCs using Nb₂CT_x-HTL treated with oxygen plasma. Reprinted with permission from ref. [124]. Copyright 2021 AIP Publishing LLC.