Time of Flight Transients in the Dipolar Glass Model

TL;DR

This study uses Monte Carlo simulations to analyze time of flight current transients in the dipolar glass model, revealing universal transient behavior, Poole-Frenkel mobility dependence, and proposing a phenomenological model that aligns with experimental data.

Contribution

It provides the first comprehensive Monte Carlo analysis of time of flight transients in the dipolar glass model, confirming universality and mobility dependence.

Findings

Transient behavior shows a flat plateau followed by $j\propto t^{-2}$ decay.

Poole-Frenkel mobility dependence confirmed across a range of fields.

Transients are universal with respect to field and sample thickness.

Abstract

Using Monte Carlo simulation we investigated time of flight current transients predicted by the dipolar glass model for a random spatial distribution of hopping centers. Behavior of the carrier drift mobility was studied at room temperature over a broad range of electric field and sample thickness. A flat plateau followed by $j\propto t^{-2}$ current decay is the most common feature of the simulated transients. Poole-Frenkel mobility field dependence was confirmed over 5 to 200 V/$\mu$m as well as its independence of the sample thickness. Universality of transients with respect to both field and sample thickness has been observed. A simple phenomenological model to describe simulated current transients has been proposed. Simulation results agree well with the reported Poole-Frenkel slope and shape of the transients for a prototype molecularly doped polymer.