Enhancing charge transfer in low-light conditions through the incorporation of carbon nanotubes in carbon-based perovskite solar cells for indoor applications.

Perovskite solar cells (PSCs) have emerged as a promising photovoltaic technology owing to their high power conversion efficiency (PCE) and low-cost fabrication, making them suitable for both outdoor and indoor applications. Nevertheless, achieving high performance under indoor lighting and ensuring long-term stability remain critical challenges. In this work, we introduce an antisolvent engineering strategy incorporating carbon nanotubes (CNTs) to enhance charge transport and suppress charge recombination. The incorporation of CNTs improves the structural and electrical properties of the perovskite film by increasing surface conductivity, thereby facilitating more efficient charge extraction and faster interfacial charge transfer, while reducing recombination losses. Consequently, the CNT-based devices exhibit an outstanding indoor PCE of 32.63% and a fill factor of 73.60% under 1000 lx LED illumination at ambient conditions (40-50% relative humidity, 25 ± 5 °C). This simple antisolvent engineering approach provides an effective pathway for developing efficient and stable carbon-based PSCs, highlighting their potential for next-generation indoor photovoltaic and self-powered electronic applications.