• Rai, Nitish
• Gao, Mei
• Ruiz-Raga, Sonia
• Simonov, Alexandr
• Sepalage, Gaveshana
• Hora, Yvonne
• Bach, Udo

Abstract

While perovskite solar cell (PSC) power conversion efficiencies (PCE) are soaring at a laboratory scale, these are most commonly achieved with thermally evaporated gold electrodes, which would present a very significant expense in large-scale production. This can be remedied through the replacement of gold with much cheaper carbon electrodes, which provide the additional advantage of not migrating through the device in contrast to metal electrodes. To this end, the present work investigates a cheap, easily available, simple to prepare aluminium-supported carbon electrode derived from a readily available paste precursors that can be applied onto various hole-transporting materials. This enabled a photovoltaic performance on par with that provided by the benchmark gold electrodes. Successful integration of this new electrode into flexible devices produced by a roll-to-roll printing technology by both pressing and lamination processes is also demonstrated. However, temperature cycling durability tests reveal that the practical use of carbon electrodes based on the commercial pastes is hindered by an incompatibility of the adhesive additives with the key components of the PSCs at elevated temperatures. Resolving this issue, we demonstrate a method to produce tailor-made graphite electrodes devoid of damaging additives, which improves the PSC stability under standard temperature cycling test protocol to the level provided by benchmark gold electrodes. The study highlights current challenges in developing laminated carbon electrodes in PSCs and proposes strategies to the resolution thereof.

Topics

• perovskite
• impedance spectroscopy
• Carbon
• aluminium
• gold
• durability