Influence of Deposition of rGO-TiO₂ and rGO-SiO₂ Films Order on the Properties of Electron Transport Layers

Abstract

The titanium dioxide (TiO₂) film has been the first consideration of the electron transport layer (ETL) production for perovskite solar cells (PSCs) using a dip procedure. In which TiO₂ layer has outstanding properties like the potential of injecting electrons between layers and stability. However, the intrinsic free electrons lost still happen on the ETL. To enhance the electrical properties of ETL, rGO was incorporated into TiO₂ (Tr) and SiO₂ (Sr), where this Sr layer is another ETL layer to form an electron transport dual-layer through optimized order deposition. In this work, the conductivity values of 4 different conditions were evaluated to select the suitable ordered fabrication of a dual-layer. Encouraging, the Tr/Sr dual-layer along with using duration in dipping step (denoted as Tr/(Sr+dip)), reaching the changing of the band gap energy (E_g), and larger grain size gained up to 15.95 nm, this certain reason might significantly ascribe boosting conductivity of ETL gained up to 604 × 10^-4 S/cm, including evidence from the reduced strain in the ETL lattice to 0.053. Eventually, this work revealed that the synergistic production of TiO₂ and SiO₂, with further incorporation of rGO into each ETL on a dual-layer, enables enhanced electrical properties, which is beneficial to the improvement of solar application quality in the future.