Fabrication and characterization of zinc oxide and polythiophene thin films as hybrid solar cell

Abstract

Hybrid solar cells are incorporating between inorganic semiconductors and organic semiconductors that potential to deliver efficient energy conversion with low-cost fabrication. The main aim is to integrate the benefits of both classes of materials. This research was focused on fabrication and characterization of zinc oxide (ZnO) and polythiophene (PT) thin films. The combination of ZnO and PT were according to the volume percentage of ZnO with 0.0%, 0.5%, 1.0%, 5.0%, 10% and 100% that coated onto indium tin oxide (ITO) glass via spin coating technique. Two types of ZnO were used in this study, one was synthesized by using zinc acetate dehydrate while the other one was the one that ready-made from Aldrich. The surface morphology of both types of particles was determined by using Scanning Electron Microscope (SEM). It showed that the morphology of synthesized ZnO was nearly the same with the one that ready­ made even though the size was larger. ZnO + PT thin films were characterized to verify their electrical properties and optical properties. The measurement of electrical conductivity was carried out with the used of Four Point Probe in two situations, in the dark and also under different intensity of light. As a result, for all volume percentage of ZnO, the electrical conductivity increased as the intensity of light was increasing due to the combination with PT. However conductivity that obtained from synthesized ZnO was lower than ready-made due to the particles sizes. In favor of optical properties, the band gap energy was diminished as the thin film absorbs more light energy. It also showed that the size of particles gave significant in the research.