Speakers

The power conversion efficiencies (PCEs) of conventional inorganic solar cells, such as Si-based ones, decline significantly under dim-light illumination conditions. On the other hand, some emerging solar technologies, such as organic solar cells (OSCs) and perovskite solar cells (PSCs), can still exhibit high PCEs under indoor and low-level lighting conditions. Therefore, they can function as promising energy sources in low-light or cloudy environments for many off-grid applications, including the Internet of Things, wearable electronics, and sensors. In this presentation, we will first review the fundamental operational mechanisms and efficiency limits, analyzing them through the Shockley-Queisser limit model under different lighting conditions, including outdoor sunlight and indoor illuminations. We will then explore various enhancement strategies, such as adjusting energy levels and bandgaps, implementing self-adaptive interfacial engineering at the anodes, and applying surface passivation to boost PCEs. Notably, indoor PSCs have achieved over 40% efficiency under optimal conditions. Lastly, the presentation will cover how machine learning models can assist in screening potential donor/acceptor materials for indoor OSCs. These advances underscore the potential of optimized merging solar cells for powering low-power electronics across diverse lighting environments, advancing toward practical, sustainable energy solutions.