Improved performance of quantum dot-sensitized solar cells by full-spectrum utilization

One of important factors for improving the power conversion efficiency (PCE) of quantum dot-sensitized solar cells is to enhance the utilization of sunlight. Herein, we modified the wavelength range of incident sunlight from the counter electrode (CE) side to investigate the photoelectric performance of solar cells. The effect of illuminating CuS and Cu 2 S CE with different light ranges (including non-illumination, UV–visible light, NIR light and full-spectrum light) on cell performance was investigated. It has been shown that illuminating from both sides of cell induce substantial increase in PCE, and a 42.8% enhancement in PCE compared with that irradiating from the photoanode side has been achieved with a champion PCE of 5.6% (Voc = 0.6 V, Jsc = 21.7 mA cm −2 ) based on CuS CE. This strategy focuses on the neglected problem of light utilization of the CE, and provides a direction for realizing full-spectrum absorption of liquid-junction solar cells.