Determination of Thin Film Thickness by Optical Simulation and RBS Techniques in Flexible Organic Photovoltaic Cells

Abstract

This paper gives a computational analysis of thin film thickness using the "Optical" software with refractive index data and results from optical measurements of an Organic Photovoltaic (OPV) with Poly-3-hexylthiophene: [6, 6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) as active layer, Polyethylene Terephthalate (PET) as substrate, ITO and Al as electrodes, and Poly (3, 4-ethylenedioxythiophene) Polystyrenesulfonate (PEDOT:PSS) as the hole transport layer. Easier deposition mechanism is employed in this research to fabricate this flexible multilayer structure. Rutherford Back Scattering (RBS) was used to confirm the ITO thickness simulated using the “Optical” Software to be 90nm as compared to the latter’s ~100nm result. Finite element analysis (FEA) done on the complete OPV device showed that the anode layer (ITO) exhibited the highest strain values compared to the other regions when flexed indicating its susceptibility to cracking.