Photocurrent Enhancement from Solid-State Triplet–Triplet Annihilation Upconversion of Low-Intensity, Low-Energy Photons

Abstract

We present a red-to-blue upconversion system based on triplet–triplet annihilation in a solid-state film configuration that significantly enhances the photocurrent of a model solar cell device. The film is robust against oxygen quenching and can be readily tailored to existing solar cell architectures. The photovoltaic performance of upconversion-assisted dye-sensitized photoelectrochemical cells was measured under both high-power coherent laser and low-power incoherent light irradiation (light-emitting diode and simulated AM1.5G sunlight). By utilizing low-energy photons that would otherwise be wasted, the photocurrent is enhanced by as much as 35% under one-sun light intensity when a model solar cell device is coupled with a TTA film and a reflector.