Interface Engineering of Graphene/CH₃NH₃PbI₃ Heterostructure for Novel p–i–n Structural Perovskites Solar Cells

Abstract

Functionalized graphene is widely used in various functional devices. Here, we introduce a simple plane capacity model and the density functional theory to investigate the origin of charge transfer in the graphene/CH 3 NH 3 PbI 3 interface, where graphene can be p-type or n-type doped by combining with different exposed surfaces of CH 3 NH 3 PbI 3 . Our calculations indicate that at the equilibrium distance, the work function of isolated graphene layer should be corrected by adding a value for assessing the charge transfer. After integrating the perovskite film with the functionalized graphene layer, we obtain a van der Waals heterostructure solar cell with a p−i−n configuration, which introduces a built-in electrical field to facilitate the separation and transport of the photogenerated carriers. The new p−i−n junction highlights the interface effect on graphene in solar cell, which offers an avenue to design new photovoltaic devices with high performance.

Effect of Surface States and Breakdown of the Schottky–Mott Limit of Graphene/Silicon van der Waals Heterostructure

“…This could explain the unusually large negative value of slope parameter for the G/S-2 × 1­(t) interfaces. This electric field direction of the pillow effect was also found in the graphene/undoped substrate interactions in recent studies, e.g., for G/MoSSe, G/CH 3 NH 3 PbI 3 , G/GaSe, G/Al­(B)­Te, and G/h-BN . Therefore, our results also imply that tuning the SBH of G/S contact could be more easily done on the n -type doped substrate than on the p -type doped substrate.…”

Theoretical Study of Using Kinetics Strategy to Enhance the Stability of Tin Perovskite

“…Since protection layer is needed not only on the grain boundaries, but also at the interface, [ 29 ] it is important to evaluate the electron transport performance [ 40 ] when protection materials are formed at the interface of perovskite and carriers transporting layers. The charge transfer at the interface is explored in the following.…”

“…Then, the charge displacement curve Δ Q , which can be used to determine the direction of charge transfer, is given by integrating along z‐direction as follows [ 40 ] :the negative value of Δ Q represents that the electrons transferred from left to right, and the positive value corresponds to the electron transfer from right to left.…”

Interface Effects in Triazine‐Based g‐C3N4/MAPbI3 Van der Waals Heterojunctions: A First‐Principles Study

“…First‐principles studies can analyze the interfacial interactions of TDMs with the perovskite at the atomic level to explore their capacity for application in PSCs and provide guidance for laboratory fabrication. Very recently, diverse TDMs such as graphene, [ 27 ] SnS, [ 28 ] black phosphorus, [ 29,30 ] and 2D perovskites [ 31 ] have been proposed to construct heterojunctions with 3D perovskites to explain the mechanism or guide experimental synthesis. Taking the hot TDM, graphene, as an example, Cao et al proposed that the contact of different surfaces of MAPbI 3 perovskite with graphene would lead to the n‐type and p ‐type doping of graphene, respectively, and then envisaged a p–i–n (or n–i–p) architecture solar cell.…”