Laboratory-Scale Reuse of Glass/ITO Substrates for Single Junction Perovskite Solar Cells

The
rapid expansion of perovskite solar cell research has led to
the daily production of hundreds, if not thousands, of laboratory-scale
solar cells worldwide, resulting in significant consumption of indium
tin oxide (ITO)-coated glass substrates. Given the scarcity of indium
and its price fluctuations due to geopolitical factors, developing
sustainable recycling and reuse strategies for glass/ITO substrates
is crucial. In this work, we present a simple and environmentally
friendly method for reusing glass/ITO substrates in a lab-scale environment,
utilizing acetone and a standard cleaning procedure that avoids toxic
solvents. Life cycle assessment (LCA) reveals that solvent use and
waste are the dominant environmental hotspots from the recycling process,
with total cradle-to-grave greenhouse gas emissions slightly lower
than fresh glass/ITO (by ∼10–30%). Pairing substrate
reuse with solvent recovery can further reduce cradle-to-grave greenhouse
gas emissions compared to a single-use substrate (by >50% for optimized
batch sizes) and to other literature processes. Importantly, solar
cells fabricated on reused glass/ITO substrates maintain the same
efficiencies (∼18%) as those on fresh substrates, even after
three reuse cycles. This study highlights the potential of ITO reuse
in research laboratories as a practical strategy to lower the environmental
footprint of solar cell research while promoting resource efficiency
and material circularity.