STRUCTURAL AND OPTICAL STUDIES OF MEH-PPV USING TWO DIFFERENT SOLVENTS PREPARED BY SPIN COATING TECHNIQUE

Abstract

Spin coating technique is commonly used to obtain uniform thin films. Conducting unsaturated polymer of red colour poly [2-methoxy-5-(2’-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV), can be easily dissolved in non-aromatic and aromatic solvents to exhibit different optical and structural properties. The MEH-PPV solutions in the two types of solvents were prepared at concentration of 8 mgml^-1. They were then spin coated onto glass and calsium difloride (CaF₂) substrates at 4 krpm for 10 seconds. The spun films of MEH-PPV on glass substrates were used for investigating the optical properties by using UV-Visible-NIR (UV-VIS-NIR) and Photoluminescence (PL) spectroscopy. The structural properties of the films were investigated by Fourier Transform Infrared (FTIR) spectroscopy. The structural transformations of the films when annealed at 76 °C and 140 ºC were also studied by analysing and comparing the FTIR spectra of the films at that specific temperature.