HIGH-CONDUCTING LEAD-DOPED REDUCED GRAPHENE OXIDE (Pbx:rGO1-x) (0.4≤X≤0.6) COMPOSITES: SYNTHESIS, OPTICAL STUDY AND IONIC TRANSPORT CHARACTERISTICS FOR OPTOELECTRONIC APPLICATION

Abstract

This research was centred on the study of the optical and ionic transport characteristics of charge carriers in the Pb doped reduced graphene oxide composite for optoelectronic application. Hummer’s method and hydrothermal reduction methods were employed in the synthesis of the composites. For sample characterisation, energy dispersive x-ray spectroscopy, scanning electron microscopy (SEM), UV Spectrophotometer analysis, four-point Probe measurement and Hall Effect measurement were used to study the chemical compositions of the composite, its morphology, its optical characteristics and the ionic transport characteristics respectively. The SEM image demonstrates how the surface coalescence breaks down with increasing dopant concentration by a slight growth in the number of grain boundaries. However, due to the fact that every samples were synthesised under the same conditions, regardless of the amount of doping, every doped composite had a very similar microstructure and surface morphology. The rGO, Pb_0.4:rGO_0.6, and Pb_0.6:rGO_0.4 have band gaps of 1.4 eV, 1.6 eV, and 1.8 eV, respectively. The ionic conductivities (electrical conductivity due to the motion of ionic charge) for rGO, Pb_0.4:rGO_0.6, and Pb_0.6:rGO_0.4 composites were determined to be 0.001341 Ω⁻¹m⁻¹, 0.002368 Ω⁻¹m⁻¹, and 0.002745 Ω⁻¹m⁻¹ respectively. The average Hall coefficient (R_H) values for the rGO, Pb_0.4:rGO_0.6, and Pb_0.6:rGO_0.4 composites, respectively, are 3.12 X 10³ m³/C, 2.57 X 10³ m³/C, and 2.88 X 10³ m³/C