CO₂ Plasma-Treated TiO₂ Film as an Effective Electron Transport Layer for High-Performance Planar Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) have received great attention because of their excellent photovoltaic properties especially for the comparable efficiency to silicon solar cells. The electron transport layer (ETL) is regarded as a crucial medium in transporting electrons and blocking holes for PSCs. In this study, CO plasma generated by plasma-enhanced chemical vapor deposition (PECVD) was introduced to modify the TiO ETL. The results indicated that the CO plasma-treated compact TiO layer exhibited better surface hydrophilicity, higher conductivity, and lower bulk defect state density in comparison with the pristine TiO film. The quality of the stoichiometric TiO structure was improved, and the concentration of oxygen-deficiency-induced defect sites was reduced significantly after CO plasma treatment for 90 s. The PSCs with the TiO film treated by CO plasma for 90 s exhibited simultaneously improved short-circuit current (J) and fill factor. As a result, the PSC-based TiO ETL with CO plasma treatment affords a power conversion efficiency of 15.39%, outperforming that based on pristine TiO (13.54%). These results indicate that the plasma treatment by the PECVD method is an effective approach to modify the ETL for high-performance planar PSCs.

A “double-sided tape” modifier bridging the TiO2/perovskite buried interface for efficient and stable all-inorganic perovskite solar cells

“…1c consists of a strong peak at a low binding energy and a shoulder peak at a high binding energy, corresponding to the bonds of lattice oxygen (O L ) and oxygen-decient defects like oxygen vacancies and hydroxyl (O D ), respectively. 27,[36][37][38][39][40][41][42][43] For the DAP modied TiO 2 sample, O 1s shis to a lower binding energy compared to that for the control one, which further evidences the interaction between DAP and TiO 2 . 35 Besides, the component concentration of O L and O D can be reected by the area ratio of the corresponding peaks, and aer modifying the TiO 2 lm with DAP, the area ratio of O L : O D is increased from 67.4 : 32.6 to 72.9 : 27.1, strongly indicating that the hydrogen phosphate anion combines with the oxygen vacancy of the TiO 2 lm to reduce the concentration of O D along with the simultaneous formation the lattice oxygen for an increased O L concentration, 20,44 which cross-veries the above analysis results and fully demonstrates that the modication of DAP effectively passivates the oxygen vacancy defects on the TiO 2 lm surface.…”

Perovskite-Based Tandem/Multi-junction Solar Cells

“…The optimized top perovskite solar cell was applied in a monolithic Perovskite-Si tandem device with a silicon bottom heterojunction cell. Although there are many alternatives, TiO2 is considered the best type of electron transparent layer and it has achieved the best results in the performance of the PSCs [69,70]. Thus, more research must be conducted on TiO2 to enhance the PCE of PSCs.…”

Analysing the Prospects of Perovskite Solar Cells within the Purview of Recent Scientific Advancements

“…The fabrication methods involve solution processable techniques such as spin-coating and dip coating. There exist other approaches such as chemical vapour deposition (CVD) [13], atomic layer deposition (ALD) [14], plasma enhanced CVD (PECVD) [15], etc., which are costlier compared to solution processable methods.…”