The sustainability of perovskite solar cell manufacturing has become increasingly critical as commercialization advances. Thermal evaporation, while providing precise control over film deposition, also generates material waste through leftover precursor in crucibles after each cycle. This study evaluates the feasibility of reusing thermally evaporated electron transport layer (ETL) materials, with no purification or chemical treatment, to address sustainability and cost-effectiveness in perovskite photovoltaics.

Two batches of perovskite solar cells, each consisting of devices with both fresh and reused ETL materials, were fabricated to assess reproducibility. The reused material was collected directly from the thermal evaporation crucible following the first deposition and applied without further processing. This design presents a straightforward approach where only the ETL layer differentiates the test groups, and all other device layers and processing steps remain unchanged. This setup permits direct assessment of whether ETL material reuse impacts device performance and stability, while minimizing extraneous experimental variables.

Device characterization utilized dark current-voltage (IV) measurements to probe charge transport properties and recombination mechanisms. Dark IV analysis reveals critical features such as interface quality, series resistance, and ideality factors, which signal the electronic properties and potential issues associated with the reused ETL. Capacitance-voltage (C-V) profiling assesses charge carrier distribution, built-in potentials, and interfacial properties, while capacitance-frequency (C-F) measurements provide trap density data and insight into defect states. These complementary techniques collectively offer a comprehensive picture of how reused ETL material influences electronic and structural device characteristics.

Device stability was investigated through three distinct methods relevant to real-world operation. Shelf-life stability was tracked by storing devices under inert conditions in a glove box and periodically measuring IV characteristics, providing insight into intrinsic material degradation and interface evolution over time. This protocol reveals stability without external stressors and serves as a baseline for degradation rates. Thermal stability was evaluated by subjecting devices to elevated temperatures to examine degradation pathways and long-term reliability, while Maximum Power Point Tracking (MPPT) stability measurements monitored device performance under continuous operation, simulating actual deployment scenarios.

The strategy demonstrates the implementation of circular economy principles for perovskite solar cell manufacturing. By reusing crucible residues without complex purification, this method addresses material waste and streamlines fabrication. Reproducibility across batches provides strong statistical validation of the protocol. Environmentally, material reuse in perovskite manufacturing is highly beneficial; recent lifecycle assessments report up to 53% reduction in global warming potential through recycling strategies. Thermal evaporation is a particularly suitable process for such recovery due to the absence of solvents and high material purity.

Results from this investigation clarify the link between material reuse cycles and device performance, supporting the development of sustainable production approaches for perovskite photovoltaics. Benchmarks for acceptable performance levels help guide future adoption and scaling of reuse strategies. This study offers a practical framework for ETL material sustainability in thermal evaporation-based perovskite solar cell manufacturing, balancing high device quality with economic and environmental benefits.