Electronic Blockade of Shunting Pathways via Dual Insulator Contacts for High-Efficiency Wide-Bandgap Perovskite Indoor Photovoltaics

Perovskite indoor photovoltaics (PIPVs) present great potential for powering Internet-of-Things (IoT)-integrated portable and low-power-consumption wireless electronics, owing to their theoretically high indoor power conversion efficiency (PCE(i)) under natural/artificial lighting conditions. Under low-light irradiance, suppressing shunting paths in PIPVs are of paramount importance to minimize interface defects induced losses in open-circuit voltage (Voc) and fill factor (FF). In this work, we propose a dual insulator contact (DIC) strategy that synergistically mitigates nonradiative recombination and shunting losses: (i) a grain boundary insulator contact (GIC) using insulating polymer poly(methyl methacrylate) (PMMA) to passivate grain boundary defects and (ii) a buried interface insulator contact (BIC) employing a hybrid PMMA/mesoporous alumina ultrathin composite interlayer to reduce heterointerface defects at the perovskite/hole transport layer junction. Leveraging this DIC approach, wide-band gap (WBG)-PIPVs achieve a PCE(i) of 44.36% (a power output of 127.94 µW cm−2) with a high Voc of 1.091 V and FF of 83.97% under a light-emitting diode (LED) (1000 lx, 288.4 µW cm−2, and 2950 K). Remarkably, the devices under LED illumination remain high indoor performance with small Voc and FF deficits even under lower irradiance, delivering PCEs(i) of 43.08% (Voc of 1.064 V and FF of 84.52%) at 600 lx, 40.24% (Voc of 1.050 V and FF of 82.97%) at 400 lx, and 40.94% (Voc of 1.020 V and FF of 82.83%) at 200 lx. The unencapsulated WBG-PIPVs also exhibit robust operational stability under continuous maximum power point tracking in under ambient LED lighting conditions, underscoring their practicality for IoT applications.