Incorporation of polymer refractive microlens array for efficiency improvement of CuInS2 quantum dot-based hybrid photovoltaic cells

Hybrid photovoltaic (HPV) cells were developed onto a flexible microlens array (MLA) in order to improve their efficiencies. The active layer of the developed HPVs was composed of blend of organic PV materials and heavy metal-free CuInS₂ quantum dots. The polymer MLA, which was replicated from isotropically etched quartz, was employed for a flexible substrate simultaneously dispersing the incident sunlight into the active layer efficiently. In illumination test, the developed HPVs integrated with the MLA exhibited highly enhanced J_SC of 6.07 mA/cm² and corresponding PCE of 1.45 %, which was 30 % improved efficiency than that of the control PVs.