LEKPV · Revolutionizing Indoor Energy: The Emergence of Low-Cost Eco-Friendly, High-Efficiency Kesterite Solar Cells

Indoor Indoor photovoltaic (IPV) cells have the potential to power distributed and remote sensors, actuators, and communication devices enabling the widespread implementation of Internet of Things. Commercial (CIGS, CdTe) and emerging (Perovskite, organic solar cells) photovoltaic technologies face several challenges for indoor applications including cost, toxicity, and stability. In contrast, kesterite materials are composed of earth-abundant, non-toxic elements and show excellent stability. This technology has recently achieved efficiencies of 14.9% under AM1.5G, demonstrating its high efficiency potential. However, its current deployment for IPV is limited by low efficiency due to the spectral mismatch with the indoor spectrum, consequence of its low bandgap (1.1 eV).This proposal aims to develop efficient kesterite solar cells with a higher bandgap tailored for IPV applications. This project will combine advanced numerical simulations with an eco-friendly DMSO process and innovative precursor ink design, novel thermal annealing, and tailored electron selective contacts which will lead to significant improvements in the device performance. The main objectives include: 1) To develop an advanced numerical model for kesterite solar cells, laying the theoretical foundation for device architecture design; 2) To design a compositionally flexible precursor ink that leads to sustainable and cost-efficient kesterite absorbers with flexible Eg (from 1.4 to 1.7 eV); 3) To synthesize high-quality kesterite films with using high-pressure thermal annealing; and 4) To deposit band-aligned electron selective contact materials for the various Eg kesterite. The project will lead to an impressive 25% efficiency for indoor kesterite solar cells and demonstrate efficient mini-modules. These original ideas will set the stage for affordable, bio-safe, and durable indoor solar cells. It also provides a technical approach for the comprehensive design of other emerging PV technologies.