Partial substitution of CdS buffer layer with interplay of fullerenes in kesterite solar cells

Over the last decades, significant progress has been made in inorganic materials to enable them as next generation photovoltaic materials that can fulfil the green energy requirements. Cu2ZnSn(S,Se)4 stands out as a p-type absorber material due to exemption from scarce and strategic elements and its similarities with Cu2InGa(S,Se)4. Organic materials based on fullerenes based derivatives are effective n-type photovoltaic materials. We report the usage of n-type fullerenes materials with kesterite-based absorbers in a thin filmpolycrystalline solar cell by a partial substitution of the CdS buffer layer with C60 or C70 fullerenes. Impedance measurements reveals that using C60 as an interlayer improve built-in potential, reduces the interface recombination and promote the charge conduction, resulting in an increase in the open circuit voltage and thus device performance.