• • Dark storage of un-screen-printed TOPCon cells for 60 days reduces minority carrier lifetime by 13% (from 4040 µs to 3522 µs), with i-Voc and i-FF dropping by 0.17% and 0.30%, respectively; this metastable decay necessitates controlled storage or pre-treatment before module assembly to avoid irreversible efficiency losses.
• • A 1-second UV pre-treatment (200 W/m², 365 nm) on 4677 industrial cells yields an average PCE gain of 0.07%, Voc increase of 0.89 mV, and FF improvement of 0.15%, demonstrating a scalable, low-cost method to recover dark-storage losses and enhance cell performance.
• • Cumulative UV irradiation up to 10^6 s (56 kW·h/m²) initially improves cell parameters but subsequently degrades passivation, leading to net PCE reduction; this threshold defines a critical process window where UV exposure transitions from beneficial to detrimental.
• • The observed anomalous efficiency enhancement is linked to hydrogen metastability: UV exposure likely redistributes hydrogen species (H⁰/H⁻) and temporarily passivates defects, but prolonged exposure generates interface states that outweigh the benefits, as evidenced by the reversal in i-Voc and i-FF trends.