Enhancing electron transport through metal oxide adjustments in perovskite solar cells and their suitability for X-ray detection

Abstract

For perovskite solar cells (PSCs) with inverted planar architectures, the widely used (6,6)-phenyl-C₆₁ butyric acid methyl ester (PCBM), as an electron transport layer (ETL), shows drawbacks such as poor film-forming and undesirable charge transfer ability. Herein, different metal oxides, including vanadium oxide (V₂O₅), manganese dioxide (MnO₂), and magnesium(II) oxide (MgO), are introduced into the PCBM ETL layer of PSCs with an FA_0.5MA_0.5PbI₃ active layer, which increases the intensity of photoluminescence, carrier lifetime and crystallinity of the perovskite film. Moreover, results for the modified ETL are extrapolated to X-ray detectors. The study sheds light on metal oxide dopant sources of the ETL in PSCs employing various physical and chemical characterization techniques. Among these metal oxides, MgO stands out as a crucial dopant that optimizes the ETL and yields a peak power conversion efficiency (PCE) of 15.12% at 2 wt% MgO. The performance of X-ray detectors is then closely examined, and it is found that the MgO-doped ETL increases sensitivity, decreases dark current, and improves charge collection efficiency. MgO (2 wt%) is found to be the ideal balance for better X-ray detector performance based on concentration-dependent analyses. The study presents comprehensive collected charge density (CCD) and dark current density (DCD) characteristics (CCD–DCD), showing that the MgO-doped ETL performs better than its counterparts with V₂O₅ and MnO₂, with a sensitivity of 4.49 mA Gy⁻¹ cm⁻² at 2 wt% MgO and a CCD–DCD of 15 μA cm⁻². These results highlight the versatility of MgO as a dopant, improving the performance of PSCs and X-ray detectors while providing insightful information for cutting-edge electronic devices in applications such as next-generation optoelectronic devices and medical imaging technologies.