Vitamin C treatment improves stability of inverted organic solar cells

February 2, 2024

A staff of researchers from the College of Southern Denmark (SDU) sought to match the advances being made in energy conversion efficiencies for natural photo voltaic cells (OPV) made with non-fullerene acceptor (NFA)  supplies with stability enhancements.

The staff chosen ascorbic acid, generally often called vitamin C, and used it as a passivation layer between a zinc oxide (ZnO) electron transport layer (ETL) and the photoactive layer of in NFA OPV cells fabricated with an inverted gadget layer stack and a semiconducting polymer (PBDB-T: IT-4F).

The scientists constructed the cell with an indium tin oxide (ITO) layer, the ZnO ETL, the vitamin C layer, the PBDB-T: IT-4F absorber, a molybdenum oxide (MoO_x) carrier-selective layer, and a silver (Ag) steel contact.

The group discovered that the ascorbic acid produces a  photostabilizing impact, reporting that antioxidant exercise alleviates the degradative processes arising from publicity to oxygen, mild, and warmth. Exams, akin to ultraviolet-visible absorption, impedance spectroscopy, light-dependent voltage, and present measurements, additionally revealed that vitamin C reduces the photobleaching of NFA molecules and suppresses the cost recombination, famous the analysis.

Their evaluation confirmed that, after 96 h of steady photodegradation underneath 1 Solar, the encapsulated gadgets containing the vitamin C interlayer retained 62% of their unique worth, with the reference gadgets retaining solely 36%.

The outcomes additionally confirmed that the steadiness-beneficial properties didn’t come at a value of effectivity. The champion gadget achieved an influence conversion effectivity of 9.97 %, an open-circuit voltage of 0.69 V, a short-circuit present density of 21.57 mA/cm2, and a fill issue of 66%. The reference gadgets containing no vitamin C, exhibited 9.85 % effectivity, an open-circuit voltage of 0.68V, a short-circuit present of 21.02 mA/cm2, and a fill issue of  68%.

When requested about commercialization potential and scalability, Vida Engmann who heads a bunch on the Heart for Superior Photovoltaics and Skinny-Movie Power Gadgets (SDU CAPE), stated, “Our gadgets on this experiment had been 2.8 mm² and 6.6 mm², however will be scaled up in our roll-to-roll lab at SDU CAPE the place we recurrently fabricate OPV modules too.”

She emphasized that the manufacturing technique will be scaled, declaring that the interfacial layer is a “cheap compound that’s soluble in typical solvents, so it may be utilized in a roll-to-roll coating course like the remainder of the layers” in an OPV cell.

Engmann sees potential for components past OPV in different third-generation cell applied sciences, akin to perovskite photo voltaic cells and dye-sensitized photo voltaic cells (DSSC). “Different natural/hybrid semiconductor-based applied sciences, akin to DSSC and perovskite photo voltaic cells, have comparable stability points as natural photo voltaic cells, so there’s a good probability they’ll contribute to fixing stability issues in these applied sciences as nicely,” she acknowledged.

The cell was offered within the paper “Vitamin C for Photo-Stable Non-fullerene-acceptor-Based Organic Solar Cells,” revealed in ACS Utilized Materials Interfaces. The primary creator of the paper is SDU CAPE’s Sambathkumar Balasubramanian. The staff included researchers from SDU and Rey Juan Carlos College.

Wanting forward the staff has plans for additional analysis into stabilization approaches utilizing naturally occurring antioxidants. “Sooner or later, we’re going to proceed investigating on this path,” stated Engmann referring to promising analysis on a brand new class of antioxidants.