Spectral Behavior of a Conjugated Polymer MDMO-PPV Doped with ZnO Nanoparticles: Thin Films

The purpose of the presented study is to examine the impact of zinc oxide nanoparticles (ZnO NPs) on the spectrum features of poly [2-methoxy-5-(3′,7′-dimethyloctyloxy)-1, 4-phenylenevinylene] (MDMO-PPV). The characteristics of the MDMO-PPV and doped ZnO NPS samples were assessed using several techniques. A set of solutions of MDMO-PPV in toluene that were doped with different ratio percentages of ZnO NPs was prepared to obtain thin films. Pristine and composite solutions were spin-coated on glass substrates. It was observed that MDMO-PPV had two distinct absorbance bands at [Formula: see text] and [Formula: see text] in its absorption spectrum. The UV-Vis spectrum was dramatically changed when [Formula: see text] of ZnO NPs were added. The result showed a significant reduction in absorption of the band [Formula: see text] , while [Formula: see text] absorption increased rapidly and became more pronounced. Upon adding (10%) ZnONPs to the sample, no noticeable change was observed in the 500 nm band. However, the 310 nm band shifted towards the blue region. There is a dominant peak in the PL spectrum of MDMO-PPV in its pristine form around [Formula: see text] and a smaller hump around [Formula: see text] of the spectrum. The spectral profile at 600 nm and the intensity of both bands are improved by raising the ZnO NP concentration. These bands feature two vibronic transitions identified as (0-0) and (0-1). When the dopant concentration increased to the maximum dopant percentage ([Formula: see text]), the energy band gap values increased by [Formula: see text] compared to the pristine MDMO-PPV. In addition, the refractive index (n) decreased to its lowest value of [Formula: see text] with the presence of concentrations of ZnO NPs.