Surface modification of perovskite active layers using heteroatom-doped porous carbon to mitigate film defects for the development of highly-efficient solar cells and X-ray detectors

Herein, we have produced porous carbon (PC) and incorporated it into perovskite precursor solutions at varying concentrations (2.5–10 vol%). This addition leads to notable improvements in the morphology and overall optoelectronic properties of the perovskite active layer (AL). The interconnected micropores and terminal oxygen sites of the PC facilitate the selective growth of perovskite crystals within these structured voids, resulting in enhanced film morphology, crystallinity, and a reduction in grain boundaries and defects in the resultant films. When integrated into perovskite solar cells (PSC), these modified films exhibit exceptional performance metrics, including a high power conversion efficiency (PCE) of 13.58 %, an impressive fill factor (FF) of 63.95 %, a substantial current density (Jsc) of 23.412 mA/cm², and a noteworthy open circuit voltage (Voc) of 0.907 V. Additionally, when the sample (CK6@AL) is incorporated into the configuration of an X-ray photodetector, it exhibits impressive characteristics, including a collected charge density (CCD-DDC) of 14.27 μA/cm², sensitivity of 4.27 mA/Gy.cm², a mobility of 5.86 × 10⁻⁴ cm²/V.s, and a trap density of 3.89 × 10¹⁵ cm⁻³. Therefore, perovskite layers modified with PC show great potential for the development of PSCs and X-ray photodetectors. This paves the way for future research into leveraging these abundant and cost-effective carbon materials, which offer high mobility and customizable morphology, further offering surface passivation at interfaces, resulting in enhanced photovoltaic properties.