Suppressed Interdiffusion and Degradation in Flexible and Transparent Metal Electrode-Based Perovskite Solar Cells with a Graphene Interlayer

Abstract

Metal-based transparent conductive electrodes (TCEs) are attractive candidates for application in indium tin oxide (ITO)-free solar cells due to their excellent electrical conductivity and cost effectiveness. In perovskite solar cells (PSCs), metal-induced degradation with the perovskite layer leads to various detrimental effects, deteriorating the device performance and stability. Here, we introduce a novel flexible hybrid TCE consisting of a Cu grid-embedded polyimide film and a graphene capping layer, named GCEP, which exhibits excellent mechanical and chemical stability as well as desirable optoelectrical properties. We demonstrated the critical role of graphene as a protection layer to prevent metal-induced degradation and halide diffusion between the electrode and perovskite layer; the performance of the flexible PSCs fabricated with GCEP was comparable to that of their rigid ITO-based counterparts and also exhibited outstanding mechanical and chemical stability. This work provides an effective strategy to design mechanically and chemically robust ITO-free metal-assisted TCE platforms in PSCs.

Progress in Materials Development for Flexible Perovskite Solar Cells and Future Prospects

“…Recently, Jeong et al. developed a Cu grid‐embedded polyimide film with graphene capping layer as TCE for fabricating fPSCs and achieved 16.4 % efficiency [165] . The graphene provided protection against the halide interdiffusion and ensured better chemical stability.…”

“…Recently, Jeong et al developed a Cu gridembedded polyimide film with graphene capping layer as TCE for fabricating fPSCs and achieved 16.4 % efficiency. [165] The graphene provided protection against the halide interdiffusion and ensured better chemical stability. Furthermore, for better chemical stability of the AgNWs, Lee et al deposited amorphous aluminum doped zinc oxide (a-AZO) deposited on the AgNW networks showed transmittance of 88.6 % and superior flexibility.…”

Review of fabrication methods of large-area transparent graphene electrodes for industry

“…PCEs are notorious for degrading (via e.g., light-induced degradation [185,186], humidity [187,188], and perovskite-metal reactions due to interdiffusion [189,190]), and even the best PSCs have lifetimes of only thousands of hours [191]. Graphene has been used as a stabilizing agent as, e.g., a protective layer [192][193][194], and transport layer [195][196][197][198][199] and electrode material [200][201][202][203].…”

Simultaneously enhancing moisture and mechanical stability of flexible perovskite solar cells via a polyimide interfacial layer

“…Polyimide (PI) is a kind of multifunctional engineering materials with a high tolerance of temperature, mechanical 100 stress. PI has been used as an additive to enhance photovoltaic performance of PSCs [19] , 101 and as foldable substrates in flexible devices [20,21]…”