Low‐Temperature and Rapid Deposition of an SnO₂ Layer from a Colloidal Nanoparticle Dispersion for Use in Planar Perovskite Solar Cells

Abstract

Deposition of the electron transport layer (ETL) is an important step in the manufacture of low‐cost, solution‐processed perovskite solar cells (PSCs). Thermal annealing processes account for a major part of the energy consumption involved in the fabrication of PSCs. The current paper presents a plasma‐based and highly convenient method (5 min, <60 °C) for the deposition of SnO2 films (PT‐SnO2) from a colloidal nanoparticle dispersion. A comparative evaluation of PT‐SnO2 films with those created by state‐of‐the‐art thermal annealing (30 min, 180 °C) (TA‐SnO2) is made herein. The key mechanism in the formation of the SnO2 layer is explained in relation to the evaporation of the dispersion medium. This comparison of PT‐SnO2 and TA‐SnO2 indicates a considerable difference in terms of energy consumption directly relevant to the low‐cost manufacture of PSCs. Photoluminescence analysis revealed no particular differences in the charge extraction of the two types of SnO2 films. The SnO2 films were subsequently employed as an ETL in planar n‐i‐p PSCs. Results revealed that the PSC resulting from PT‐SnO2 yielded an efficiency of 15.17%, similar to that of 15.91% corresponding to TA‐SnO2. In addition, the PSC fabricated on the PT‐SnO2 maintaining ≈80% of its initial performance after 21 days in ambient conditions.

Low-temperature solution-processed SnO2 electron transport layer modified by oxygen plasma for planar perovskite solar cells

“…The origin of HI in PSC is multifactored, as it can be attributed to either charge accumulation at the interface or other reasons, such as ion migration in MAPbI 3 . 7 Therefore, the low HI for LTP-SnO 2 is mainly due to the low charge accumulation at the interface of ETL/MAPbI 3 , as evidenced by previous TRPL results that show a low s avg value. It was also reported that the large grain size of MAPbI 3 also reduces HI.…”

“…[1][2][3][4][5][6] Generally, n-i-p planar structures are employed in most state-of-the-art PSCs where the perovskite light-absorbing layer is sandwiched between the ETL and HTL. 7 Appropriate selection of the ETL plays a dominant role in determining the performance of PSCs by effectively extracting and transporting photogenerated electrons from the perovskite layer to the electrodes. Recently, extensive research has been focused on metal oxide-based ETLs, such as TiO 2 , SnO 2 , ZnO, InO 3 , and Nb 2 O 5 , for planar structure-based PSCs.…”

Robust electron transport layers of SnO2 for efficient perovskite solar cells: recent advances and perspectives

“…Shekargofta et al deposited SnO 2 thin films with uniform and highly crystalline surfaces at 60 °C through Ar plasma treatment of spin-coated SnO 2 precursors. 80 Compared with the SnO 2 film treated by traditional thermal annealing, the surface of the SnO 2 film treated with Ar plasma is very smooth and pinhole-free. Most importantly, the stability of the PSCs based on Ar plasma-treated SnO 2 is better, maintaining 80% of the initial performance after 504 h under environmental conditions.…”

Fabrication of low-cost and flexible perovskite solar cells by slot-die coating for indoor applications

“…For a faster annealing process, as is preferable in a R2R process, a 5 min long atmospheric pressure plasma can be used instead. 12 The air-knife was not required for this deposition.…”