Ag2S quantum dot-sensitized WO3 photoelectrodes for solar cells

This work investigates the photovoltaic properties of new-architecture Ag2S quantum dot-sensitized solar cells (QDSCs) fabricated on WO3 electrodes. Liquid-junction Ag2S QDSCs were fabricated from QDs synthesized using the successive ionic layer adsorption and reaction process. The optimal QDSC yielded an efficiency η of 0.20 % under a 100-mW/cm2 light illumination. Coating the QDSC with a compact layer and a scattering layer improved η to 0.31 % with a short-circuit current density Jsc of 5.81 mA/cm2 and an open-circuit voltage Voc of 0.21 V. η increased to 0.53 % at a reduced 0.1 sun illumination with a Jsc of 1.11 mA/cm2. The external quantum efficiency (EQE) spectrum covered the spectral range of 350–900 nm with a maximal EQE of 29 % at λ = 650 nm. This work demonstrates the feasibility of the new-configuration Ag2S QDSCs fabricated on WO3 electrodes.