Concentrated perovskite photovoltaics enable minimization of energy loss below 0.5 eV under artificial light-emitting diode illumination

Artificial light cells (ALCs) are potential energy suppliers for self-powered internet-of-things. Recently, perovskite semiconductors have emerged as promising harvesters for recycling the energy from artificial lights; however, its corresponding ALCs have suffered from high energy loss (E_loss) over 0.6 eV caused by the insufficient trap passivation and the limited splitting of the quasi-Fermi levels under dim light conditions. Here, we achieved highly efficient perovskite ALCs up to 42.1% power conversion efficiency by optimizing the photo-active layer and concentrating light from artificial light-emitting diodes (LEDs). In this work, we modified the perovskite ALCs by composition engineering, interfacial treatment, and thickness control, resulting in the reduced trap density and enhanced light collection. We found that perovskite ALCs under the ×32 concentrated 1000 lx LED afford an improved V_OC of 1.10 V with a reduced E_loss of 0.48 eV compared to the devices under nonconcentrated light (V_OC = 0.96 V and E_loss = 0.62 eV). More importantly, due to the absences of ultraviolet and infrared wavelengths in artificial LED light sources, the perovskite ALCs have higher stability under concentrated LED illumination than devices under outdoor sunlight.