Entropy-assisted nitrogen-doped carbon-anchored high-entropy alloy composites for efficient and stable universal photovoltaic electrode

Abstract

High-entropy alloys (HEAs) show high-entropy due to synergy among their multiple constituent elements as well as lattice distortion. However, the low nanoparticle dispersion and conductivity of HEAs hinder their application in photovoltaic electrodes. We developed an entropy-assisted strategy that involves Zn metal–organic framework (MOF)-derived pyrolysis. This strategy constructs N-doped Carbon-anchored high-entropy alloy nanoparticle composites (HEA NPs@NC). Transmission electron microscopy confirmed the uniform dispersion of the HEA NPs on a N-doped conductive C support. N doping enhances charge transfer, whereas entropy-assisted alloying modulates the work function and increases electrocatalytic activity of the HEA. The HEA NPs@NC electrode demonstrated applicability for two devices. The catalytic activity of the HEA NPs@NC electrode was the highest toward the I₃⁻/I⁻ redox reaction in sensitized solar cells. The power conversion efficiency (PCE) was 8.34%, which higher than that of the Pt electrode (7.20%). The work function (5.02 eV) of the electrode in carbon-based hole transport layer-free perovskite solar cells closely aligned with the perovskite valence band. This work function efficiently extracted holes, with a PCE of 14.78%, retaining 92% of the initial efficiency after 30 days. This design strategy for entropy-assisted electrodes is widely applicable and cost-effective, producing electrodes that ensure stable and efficient photovoltaic processes.