| Work Detail |
Chinese researchers have fabricated a perovskite-silicon tandem solar cell that uses an indium oxide buffer layer to protect the perovskite absorber and electron transport layer from potential damage during the electrode deposition process. The new layer not only provided this protection, but also exhibited excellent optical and electrical properties.
Researchers at Northwestern Polytechnic University in China have fabricated a semitransparent four-terminal (4T) perovskite-silicon tandem solar cell based on a top perovskite cell integrating an indium oxide (In2O3) sputtering buffer layer (SBL) deposited by a low-cost method for industrial applications.
SBLs are used in perovskite-silicon tandem devices to prevent sputtering damage during the deposition of the transparent indium tin oxide (ITO) electrode, protecting the underlying perovskite absorber and electron transport layer (ETL).
“The In2O3 SBL was fabricated using electron beam evaporation, a solvent-free process compatible with industrial production,” lead author Li Can told pv magazine . “The optical and electrical properties of the In2O3 film were highly dependent on the deposition rate. Higher deposition rates resulted in In-rich In2O3 films with low transmittance and higher parasitic absorption. By optimizing the deposition rate, we achieved stoichiometric In2O3 films with high transmittance and strong shielding properties.”
The research team constructed the superior perovskite device with a glass and ITO substrate, a nickel(II) oxide (NiO) self-assembled monolayer (SAM), the perovskite absorber, a buckminsterfullerene (C60)-based ETL, a bathocuproine (BCP) buffer layer, the In2O3 SBL, and the ITO electrode.
This cell achieved an energy conversion efficiency of 20.20%, close, according to the scientists, to that of its opaque counterpart, while displaying the excellent electrical, optical and protective properties of the In2O3 layer, whose energy bandgap is 1.68 eV.
“In2O3 films with a thickness of 20 nm effectively protected the underlying perovskite film and the ETL from damage caused by bombardment during ITO sputtering,” Can explains. “Various characterizations, such as cross-sectional SEM, X-ray diffraction, and steady-state photoluminescence, confirmed this superior protection effect.”
The academics then integrated the upper perovskite cell with a lower silicon cell into a tandem device that achieved an efficiency of 30.04%. This cell was also able to retain around 80% of its initial efficiency after 423 h of continuous light. They claim that the cell is one of the highest-performing 4T perovskite-Si tandem solar cells to date.
The device description is available in the study “ Indium oxide buffer layer for perovskite/Si 4-terminal tandem solar cells with efficiency exceeding 30%,” published in the Journal of Energy Chemistry .
“Our work expands the limited selection of SBL materials available for pin-structured ST-PSCs and introduces a low-cost deposition approach for industrial applications,” Can concludes. “This work demonstrates significant potential for accelerating the commercialization and widespread application of perovskite photovoltaics.” |
