Carbon Electrodes for Efficient Low-Light Perovskite Photovoltaics in IoT Applications

As the Internet of Things (IoT) and other emerging technologies expand to address societal challenges, the demand for sustainable and efficient power solutions has become increasingly critical to unlock their full potential. With 40 billion connected IoT devices predicted by 2030, traditional battery reliance poses significant challenges.
Ambient light harvesting via perovskite photovoltaics offers a promising solution, attracting substantial research interest due to their solution-processability, tuneable bandgaps, high defect tolerance, broad absorption spectra, and long charge carrier diffusion lengths. These attributes have led to rapid advancements, resulting in power conversion efficiencies exceeding 25% under 1-sun illumination and over 40% in low-light conditions. However, industrial scalability is hindered by the reliance on expensive noble metal electrodes, toxic solvents, and costly manufacturing processes. Additionally, stability under real-world conditions, remains a significant concern.
This work considers the role played by the carbon electrode in the performance of a perovskite solar cell under low light conditions. These electrodes present a scalable and cost-effective alternative to evaporated metal electrodes, offering improved long-term stability even when considering protected internal conditions.
Our research explores the potential of carbon-based perovskite devices for efficient energy harvesting in both 1-sun and low-light conditions. We investigate planar and mesoscopic device architectures at the cell scale, prioritizing the use of sustainable and abundant materials. Our approach uses low-toxicity ACN as the precursor solvent for roll-to-roll (R2R) coating of the planar stack and the green solvent GVL for screen printing of the mesoscopic stack, both supporting scalable and efficient fabrication of perovskite devices. In doing so, we achieve PCEs of 27.3% under 50 Lux LED-B4. Our research demonstrates that carbon-electrode based perovskite photovoltaics aligned with long-term sustainability considerations can achieve performance comparable to traditional gold electrodes for low light applications.
The talk will conclude with a fully laser-scribed 5x5 cm perovskite minimodule and its performance in an energy harvesting IoT sensor system.