Of course, the composition of the material that is used as the counter electrode is extremely important to creating a working photovoltaic, as the valence and conduction energy bands must overlap with those of the redox electrolyte species to allow for efficient electron exchange.
In 2018, Jin et al. prepared ternary nickel cobalt selenide (NiCoSe) films at various stoichiometric ratios of nickel and cobalt to understand its impact on the resulting cell performance. Nickel and cobalt bimetallic alloys were known to have outstanding electron conduction and stability, so optimizing its stoichiometry would ideally produce a more efficient and stable cell performance than its singly metallic counterparts. Such is the result that Jin et al. found, as NiCoSe achieved superior power conversion efficiency (8.61%), lower charge transfer impedance, and higher electrocatalytic ability than both its platinum and binary selenide counterparts.