| Work Detail |
An international research group has unveiled the first perovskite solar cells on polycarbonate substrates, suitable for flexible photovoltaic applications. Using an industry-compatible manufacturing method, the group produced devices with a power conversion efficiency of 13.0%, 87% of which was maintained after 1000 bending cycles within a 20 mm radius.
An international research group has demonstrated a method for manufacturing perovskite solar cells on polycarbonate substrates that is compatible with industrial production processes for flexible photovoltaic devices.
“Here we developed the first perovskite solar cell on polycarbonate sheets with a power conversion efficiency of 13.0% by developing a sheet-coated planarization layer that also provided the necessary solvent resistance,” Zeynab Skafi, first author of the study, told pv magazine .
Tests indicated that 87% efficiency is maintained after 1000 bending cycles within a 20 mm radius. “Dark storage (ISOS-D-1) and thermal stability (ISOS-T-1) tests showed T80 values ??of 1776 h and 144 h, respectively,” the group explained.
He also noted that these values ??could eventually be improved by applying ultra-high permeability barriers, as previous research has shown that they reduce water vapor transmission rates by three orders of magnitude.
Noting that polycarbonate has advantages over other flexible substrates such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) due to its relatively high glass transition temperature and low moisture absorption, the team noted that it has “excellent transparency” of 90% in the visible spectrum, comparable to that of PET and PEN, at 90% and 88.7%, respectively.
He added that polycarbonate had not been used for this type of application before despite other advantages, such as being lightweight, flexible and low-cost. “Until now, polycarbonate has never been used for this purpose, even though it has a huge market, not far behind that of PET and much larger than that of PEN, due to its poor solvent resistance and high surface roughness,” corresponding author Thomas M. Brown told pv magazine .
The team addressed the roughness and solvent resistance issues by applying a planarizing layer of commercial, ambient-cure refractory resin using a blade-coating method.
This step reportedly reduced “surface roughness from 1.46 µm to 23 nm, and cut the water vapor transmission rate in half, which “significantly improved” solvent resistance and enabled the deposition of precursor inks.”
In the experiment, perovskite solar cells were fabricated as follows: a polycarbonate and indium tin oxide (ITO) substrate, a tin oxide (SnO2) electron transport layer, a perovskite layer, a Spiro-MeOTAD-based hole transport layer, and gold (Au) contacts. The ITO layer was optimized by controlling the transmittance, sheet resistance, surface roughness, and all layers except the two electrodes were solution processed at low temperatures below 100 C.
The team noted that the fabrication process is “compatible with low-cost manufacturing” and allows for integration with other printed electronic components.
The researchers concluded that combining perovskite cells with polycarbonate sheets enables light-harvesting capabilities to be integrated into a wide range of indoor and outdoor applications. “Opening up the flexible solar cell market to new substrate materials can play an important role in future energy harvesting, powering future electronic devices, and contributing to rapidly growing markets such as smart windows, skylights, buildings, digital cards, and smart IDs,” Brown said.
The results are detailed in “ Flexible Perovskite Solar Cells on Polycarbonate Film Substrates,” published in Advanced Energy Materials .
The research group consisted of Italian researchers from CHOSE (Center for Hybrid and Organic Solar Energy) of Tor Vergata University, ENEA Frascati Research Center, Halocell Europe and Istituto di Struttura della Materia, together with scientists from the Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology (FEP) in Germany and the University of Guilan (Iran). |
