Operational stability study of hole transport-free perovskite solar cells using lithium fluoride in electron transport layer

• Published in: Journal of materials science. Materials in electronics Vol. 34; no. 7; p. 592
• Main Authors: Noori, Darko A., Behjat, Abbas, Dehghanipour, M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-03-2023; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Charge transfer; Chemistry and Materials Science; Contact angle; Dopants; Electric contacts; Electrical resistivity; Electron transfer; Electron transport; Energy conversion efficiency; Fluorides; Lithium; Lithium fluoride; Materials Science; Optical and Electronic Materials; Optical properties; Perovskites; Photovoltaic cells; Solar cells; Titanium dioxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-023-09868-9

The stability problem of perovskite solar cells (PSCs) as a challenging issue has not been ideally treated. In this regard, the electron transport layer (ETL) plays a decisive role in regulating the performance and stability of PSCs. We present here a lithium fluoride (LiF) additive in mesoporous titanium dioxide (mp-TiO
2
) with different volume concentrations (0–7, v%) as ETL in mesoscopic PSCs. The electrical, optical, and morphological properties of the ETL/perovskite layer are investigated. Herein, we report the LiF dopants which not only give rise to the uniformity surface of the ETL and perovskite layers but also take fast electron transfer with reduced charge recombination. Overall, our findings show that the 2.5% LiF-doped mp-TiO
2
sample has the optimum electrical conductivity (1.44 × 10
−3
mS.cm
−1
) and contact angle (23.68°). Moreover, the average crystalline size (332 nm) and the highest contact angle (59.40°) of the perovskite layer are measured. Notably, the LiF dopant increases the shelf stability of the treated samples. The optimized device shows an enhancement of 46% in power conversion efficiency compared with the reference samples and maintained 90% for 111 days of aging time in the absence of a hole transporting layer.