Simulation of Charge Carrier Mobility in Conducting Polymers
- Saturday, 01 March 2014
Electric conduction in polymers is one of the key elements in avoiding catastrophic internal electrostatic discharge in dielectrics during space missions. This software package enables the simulation of carrier mobility for any given site concentration, which is a material design parameter that can be varied in experimental studies. The software computes the charge mobility for a disordered network of carrier sites. The mobility is obtained by computing the average drift velocity for an applied electric field. The mobility is given by the ratio of the drift velocity to the electric field.
The software uses an efficient Monte Carlo technique to sample the transit time of carriers injected on one end of the simulation domain. The mobility can be obtained as a function of temperature and site concentration, which are parameters of interest for experiments and materials design.
This software is implemented in C++ and is highly modular. New models and variations in the simulation process can easily be added. Parallelization for execution on a distributed computing platform was implemented.
This program enables the calculation of charge mobility in polymers with varying dopant concentration, as a function of electric field and temperature. The objective is to use this program to explore the parameter space and identify the material parameters that best meet the design requirements. The program will be used to optimize a new material system and will help solve the problem of catastrophic internal electrostatic discharges in dielectrics, which is one of the largest sources of anomaly or failure in space missions. Deep space missions to the outer planets and their moons, where the radiation environment is particularly harsh, will benefit most from the new modeling capability.