Theoretical analysis of earth-abundant solar cell based on green absorber CuFeO2

Huge advancements in the understanding of photovoltaic (PV) physics have been made, but still, PV has not overtaken conventional energy sources due to PV materials cost, toxicity, and stability concerns. In the pursuit of discovering a new solar energy harvester which satisfies criteria such as low cost, earth-abundance, non-toxicity, high efficiency and long-term stability, extensive research has been conducted on the potential of copper iron oxide (CuFeO2), also known as delafossite oxide. CuFeO2 possesses optimal bandgap (1.5 eV), with a high absorption coefficient and carrier mobility, suitable for potentially cost-effective solar cells. Theoretical modelling based on the optical and electrical characteristics of the CuFeO2 system is performed here on delafossite CuFeO2 to examine its photovoltaic performance. We explored various buffer counterparts for CuFeO2 absorber, and a stack of p–n+–n++is simulated for device optimization. ZnO showed zero conduction band offset with CuFeO2 and a corresponding efficiency of 28% for CuFeO2/ZnO/ITO (p–n+–n++) device. The optimal range of crucial design parameters, such as doping profile, absorber thickness, surface recombination velocity, back contact work function, resistances, and bulk defects, that allow CuFeO2 solar cells to reach power conversion efficiencies above 25% are quantified. The spectrum loss (thermalization and non-absorption loss) stands at 59.6%, extrinsic recombination loss at 12.3%, and the performance ceiling of CuFeO2 at 28.1%. Theoretical analysis shows that the maximum achievable efficiency of 28% is close to the Shockley–Queisser (S–Q) limit and comparable to contemporary inorganic solar cells. The findings presented in this study are anticipated to stimulate experimentalists to fabricate stable, high-efficiency CuFeO2-based thin film solar cells.