Effect of temperature on electrical resistivity of EVA-LDPE nanocomposites for photovoltaic encapsulating application: An activation energy method

Abstract

This article evaluates the effect of mixing strategy on thermo-electrical resistance of ethylene vinyl acetate (EVA), low-density polyethylene (LDPE) and fumed silica nanoparticles (FSN) based composite encapsulating materials. The nanocomposites were synthesized by solution compounding method with various sequence of ingredients addition. The quantity of ingredients is same for all nanocomposites where the ratio of EVA, LDPE and FSN addition is 10:1:0.11. The structural morphology of the samples prepared by different mixing sequence was studied under Transmission Electron Microscopy (TEM). DC volume resistivity (VR) were evaluated at 25 °C, 50 °C and 75 °C for all the compositions to check the insulation behaviour at extreme service temperature as VR is an assessing parameter for photovoltaic (PV) encapsulating materials. For obvious reason, the magnitude of VR decreases with increasing temperature. Activation energy (Ea ) was estimated from Arrhenius equation and the value evaluated was very much dependent on the ingredients mixing strategy. Good electrical resistance with desired activation energy were obtained for the nanocomposites; prepared with a particular mixing strategy where percolation threshold achieved. Finally, the TEM structure and insulation property relationship has been addressed against the experimental findings.