Charge transfer balancing of planar perovskite solar cell based on a low cost and facile solution-processed CuOx as an efficient hole transporting layer

• Published in: Journal of materials science. Materials in electronics Vol. 32; no. 2; pp. 2312 - 2325
• Main Authors: Makenali, Marzieh, Kazeminezhad, Iraj, Ahmadi, Vahid, Roghabadi, Farzaneh Arabpour
• Format: Journal Article
• Language: English
• Published: New York Springer US 2021; Springer Nature B.V
• Subjects: Acidic oxides; Characterization and Evaluation of Materials; Charge transport; Chemistry and Materials Science; Copper oxides; Electrochemical impedance spectroscopy; Film thickness; Glove boxes; Materials Science; Optical and Electronic Materials; Perovskites; Photovoltaic cells; Solar cells
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-020-04996-y

Planar perovskite solar cells are known for their ease of fabrication and considerable efficiency. Hole transport layer in these cells is however mostly either expensive organic spiro-OMeTAD or hydrophilic PEDOT: PSS polymer which reduces cell lifespan due to its acidic nature. Copper oxide, on the other hand, is a non-toxic inorganic alternative. It can be synthesized through a facile solution-based process, requiring no vacuum system or N 2 glovebox, which makes it conveniently adaptable to large-scale production. Inverted planar perovskite solar cells with CuO x as hole transport layer were studied. To balance the charge transfer in the device and avoid the charge accumulation in the bulk and interfaces, CuO x layer was deposited with different thicknesses. As verified by PL tests, quenching of the deposited CuO x layer was comparable to PEDOT: PSS layer which signifies its effectiveness as a hole transport layer. Optimum observed results were for a cell with an efficiency of 6.26%, V oc of 0.71 V, J sc of 12.87 mA/cm 2 , and fill factor of 0.69. Consistent with J–V measurements, electrochemical impedance spectroscopy indicated a significant increase in charge transport resistance between hole transport layer and perovskite film as the CuO x film thickness was increased from 55 nm to 75 nm.