CdS/CdSe/PbS quantum dots sensitized TiO2 eggshell hollow microspheres photoanode to boost photocurrent and power conversion efficiency of QDSSC

Abstract

Light harvesting plays crucial role for high photovoltaic performance of quantum dots sensitized solar cell (QDSSC). However, there are still issues need to be tackled, such as enlarging light response range and enhancing light scattering capability. In this work, TiO2 eggshell hollow microspheres (EHMS) were synthesized by carbonaceous microspheres (CMS) template method and co-sensitized by CdS/CdSe/PbS quantum dots (QDs) for application in QDSSC. Compared with QDSSC based on TiO2 nanoparticles (NP) and TiO2 hollow microspheres (HMS), the TiO2 EHMS based QDSSC showed a remarkable increase of short-circuit current density (Jsc) to 24.81 mA cm−2 with a power conversion efficiency (PCE) of 4.07 %. Photoelectrochemical analysis of QDSSC indicate that CdS/CdSe/PbS QDs can enlarge the light response range, and the TiO2 EHMS improve the light scattering, leading to the improvement of light harvesting efficiency. Charges dynamics tests results proved that a larger charges recombination resistance at photoanode/electrolyte interface and longer electron lifetime can be achieved with TiO2 EHMS, contributing to the boost of Jsc. The presented study introduces a simple strategy for researchers interested in designing photoanode for various photoelectrochemical applications.