Trap Modulated Charge Carrier Transport in Polyethylene/Graphene Nanocomposites

Abstract

The role of trap characteristics in modulating charge transport properties is attracting much attentions in electrical and electronic engineering, which has an important effect on the electrical properties of dielectrics. This paper focuses on the electrical properties of Low-density Polyethylene (LDPE)/graphene nanocomposites (NCs), as well as the corresponding trap level characteristics. The dc conductivity, breakdown strength and space charge behaviors of NCs with the filler content of 0 wt%, 0.005 wt%, 0.01 wt%, 0.1 wt% and 0.5 wt% are studied, and their trap level distributions are characterized by isothermal discharge current (IDC) tests. The experimental results show that the 0.005 wt% LDPE/graphene NCs have a lower dc conductivity, a higher breakdown strength and a much smaller amount of space charge accumulation than the neat LDPE. It is indicated that the graphene addition with a filler content of 0.005 wt% introduces large quantities of deep carrier traps that reduce charge carrier mobility and result in the homocharge accumulation near the electrodes. The deep trap modulated charge carrier transport attributes to reduce the dc conductivity, suppress the injection of space charges into polymer bulks and enhance the breakdown strength, which is of great significance in improving electrical properties of polymer dielectrics.

Polyethylene/Graphene Nanoplatelet Nanocomposite-Based Insulating Materials for Effective Reduction of Space Charge Accumulation in High-Voltage Direct-Current Cables

“…The increase in volume resistivity of the nanocomposite compared to the neat LDPE was greater at an electric field of 20 kV/mm; their volume resistivity values were 1 3 × 10 16 Ω • cm (@ 0 wt%), 9 4 × 10 16 Ω • cm (@ 0.01 wt%), 7 4 × 10 16 Ω • cm (@ 0.05 wt%), and 8 6 × 10 16 Ω • cm (@ 0.1 wt%). According to a previous study on trap level distribution of insulating 7 Journal of Nanomaterials increase the average hopping distance for the charged carriers, thus suppressing the transport of charged carriers [17]. From these results, it is believed that dielectric GNP-T fillers (below the content of percolation threshold) can effectively capture charged carriers injected from the electrode, resulting in an increase in the volume resistivity of the nanocomposite rather than neat LDPE.…”

“…The charging current in the electric field of 10 kV and 20 kV was measured by electrometer for 7,200 seconds. Then, volume resistivity was calculated by the following equation [17]:…”

“…[11][12][13][14][15] and nanocarbons (κ = 10~15, carbon black, graphene, etc.) [16][17][18] have mainly been studied as nanofillers acting as charge trapping sites. Such nanofillers are known to provide charge traps in the polymer matrix that reduce the mobility of charged carriers, including electrons, holes, and polar species.…”

Dielectric behavior and structural characterization of polymeric double layer thin films

“…Interfacial phenomena, as well as bulk properties, are known to play important roles in the electrical behavior of polymeric insulating materials. The polymeric interfaces act as charge‐carrier trapping sites in layered polymers . Therefore, it has become essential to study the effect of interfaces on charge‐carrier transport and storage, because most practical insulators are composites of several insulators and semiconductors.…”

Feasibility of polyethylene film as both supporting material for transfer and target substrate for flexible strain sensor of CVD graphene grown on Cu foil

“…Flexible substrates, such as polyethylene (PE) lm, are suitable for graphene-based wearable sensors. [27][28][29] Although graphene transfer methods based on exible polymer lms exist, 30 little attention has been paid to making wearable sensors on polymer lms. 31 Herein, we report the preparation of a wearable sphygmus sensor based on transferred graphene on PE lm.…”