Self-Powered Organic Photodetectors with Record Bandwidth for Simultaneous Energy Harvesting and High-Speed Optical...

Organic photodetectors (OPDs) are attracting increasing interest as receivers for visible light communication (VLC) systems due to their high sensitivity, low-cost fabrication, and mechanical flexibility. Recent efforts have focused on self-powered OPDs that can simultaneously enable data reception and energy harvesting. Here, we systematically investigate the effect of charge transport layer (CTL) composition on the dynamic performance of self-powered PM6:Y6 OPDs. Frequency response measurements show that devices employing inorganic CTLs deliver a significantly higher 3-dB bandwidth of 1.85 MHz compared to 1.10 MHz for organic CTLs, while OPDs with organic CTLs yield superior photovoltaic efficiency. In VLC demonstrations, OPDs with inorganic CTLs achieve a record usable modulation bandwidth of 52.9 MHz, substantially higher than previously reported values (∼30 MHz). Importantly, these OPDs support a record high-speed data transfer rate of 160 Mbs-1 while simultaneously harvesting 10 mW cm-2 of electrical power. Transient photocurrent and capacitance-voltage (C-V) analyses indicate that the enhanced response speed in inorganic CTL devices arises from faster charge extraction and reduced trap-related charge accumulation. These findings underscore the critical role of CTL selection in advancing self-powered OPDs for integrated high-speed optical communication and energy harvesting.