Focussed Review of Utilization of Graphene-Based Materials in Electron Transport Layer in Halide Perovskite Solar Cells: Materials-Based Issues

Abstract

The present work applies a focal point of materials-related issues to review the major case studies of electron transport layers (ETLs) of metal halide perovskite solar cells (PSCs) that contain graphene-based materials (GBMs), including graphene (GR), graphene oxide (GO), reduced graphene oxide (RGO), and graphene quantum dots (GQDs). The coverage includes the principal components of ETLs, which are compact and mesoporous TiO2, SnO2, ZnO and the fullerene derivative PCBM. Basic considerations of solar cell design are provided and the effects of the different ETL materials on the power conversion efficiency (PCE) have been surveyed. The strategy of adding GBMs is based on a range of phenomenological outcomes, including enhanced electron transport, enhanced current density-voltage (J-V) characteristics and parameters, potential for band gap (Eg) tuning, and enhanced device stability (chemical and environmental). These characteristics are made complicated by the variable effects of GBM size, amount, morphology, and distribution on the nanostructure, the resultant performance, and the associated effects on the potential for charge recombination. A further complication is the uncertain nature of the interfaces between the ETL and perovskite as well as between phases within the ETL.

A review of graphene derivative enhancers for perovskite solar cells

“…Hence, electron/hole recombination rates are lowered by the ETL through electron extraction and transfer enhancement. 173 The tuning of the ETL surface energy is a feasible control protocol for wettability, recrystallization and nano-structural parameters of perovskites. 173 With reference to the PSC structure, the n–i–p type is largely influenced by the electrical, optical and structural features of an ETL.…”

“… 173 The tuning of the ETL surface energy is a feasible control protocol for wettability, recrystallization and nano-structural parameters of perovskites. 173 With reference to the PSC structure, the n–i–p type is largely influenced by the electrical, optical and structural features of an ETL. 35 Common ETLs for the n–i–p structure are oxides, such as TiO 2 , 34 SnO 2 and ZnO.…”

“…Interestingly, graphene derivatives are compatible with metal oxides that function in ETLs to form meso-super-structured PSCs with preferred properties (Table 1), 25 such as increased semiconducting properties, 121,173 device stability and charge extraction. 27 For illustration, the inclusion of RGO within TiO 2 layers of PSCs produced a PCE boost of 21%.…”

Impedance Spectroscopy Analysis of Perovskite Solar Cell Stability

“…Doping the ETL with metals such as antimony (Sb), lithium (Li), Niobium (Nb) or other materials is another common and effective approach used to reduce defects and enhance the charge transfer ability [27]. Among the different studies, some highlight the beneficial role of graphene as a dopant in SnO 2 [28][29][30][31][32]. The principal advantage of graphene is its capacity to improve the intrinsic semiconducting properties of the ETL and to alter its surface and volume morphologies in a beneficial manner.…”

Methylammonium Lead Bromide Perovskite Nano-Crystals Grown in a Poly[styrene-co-(2-(dimethylamino)ethyl Methacrylate)] Matrix Immobilized on Exfoliated Graphene Nano-Sheets

“…Graphene nano-sheets possessing different chemical groups have been proposed as nanostructured scaffolds for the growth, stabilization, and properties tuning of perovskite nano-crystals. To note, graphene nanosheets have excellent charge transport properties and have been widely exploited as charge transport layers in perovskite solar cells [3][4][5][6]. A large effort has been put into the design of tightly interacting graphene/perovskite interfaces.…”