Expanding light utilization to the near-infrared region for hybrid bio–photoelectrochemical cells

The insatiable energy demand asks for the maximum conversion of green renewable sources. Herein, we propose the first NIR-assisted glucose/air bio-photoelectrochemical (BPEC) cell comprising a rare earth up-conversion microcrystal (UCMC)-based polyterthiophene (pTTh) cathode. Upon irradiation with a 980 nm laser, UCMCs emit robust luminescence in the visible range, which can efficiently excite pTTh, catalyzing the reduction of oxygen and generating photocurrent. Coupling with a glucose oxidation bioanode, this assembled BPEC cell exhibits a maximal output power density of 40.6 μW cm^-2 and an open circuit voltage of 0.53 V. This success is an essential conceptual steppingstone towards the comprehensive utilization of whole sunlight and offers alternative solutions for multiple energy conversions.