Effect of the grain size of nanoparticle dye‐coated titanium dioxide on the short‐circuit current density and open‐circuit voltage of an indium tin oxide/titanium dioxide/poly(acrylonitrile)–propylene carbonate–lithium perchlorate/graphite solar cell

Abstract

A dye-sensitized indium tin oxide (ITO)/titanium dioxide (TiO 2 )/polyacrylonitrile (PAN)-propylene carbonate (PC)-lithium perchlorate (LiClO 4 )/graphite solar cell was fabricated, and its performance was tested in the dark and under the illumination of a 100 mW/cm 2 light. Three TiO 2 samples were used in the device, namely, uncoated TiO 2 , a TiO 2 film coated with methyl red dye, and a TiO 2 film coated with coumarin dye. The films were deposited onto an ITO-covered glass substrate by a controlled hydrolysis technique assisted with a spin-coating technique. The films were characterized by scanning electron microscopy to determine their average grain size. The smallest grain size (48 nm) was obtained for the uncoated film. An electrolyte of PAN-LiClO 4 with PC plasticizer was prepared by a solution-casting technique. A graphite electrode was prepared on a glass slide by an electronbeam evaporation technique. The device showed rectification properties in the dark and showed a photovoltaic effect under illumination. The device with the uncoated TiO 2 film showed the highest short-circuit current density (2.0 lA/cm 2 ) and an open-circuit voltage of 0.64 V because it possessed the smallest grain size.