Non-Linear I-V Characteristics of Double Schottky Barriers and Polycrystalline Semiconductors

TL;DR

This paper theoretically analyzes the highly non-linear I-V characteristics of polycrystalline semiconductors, focusing on the effects of double Schottky barrier fluctuations at grain boundaries and their role in electrical breakdown phenomena.

Contribution

It introduces a binary mixture model for barrier height fluctuations and proposes a new form to accurately reproduce breakdown voltage and non-linearity in I-V behavior.

Findings

Barrier height fluctuations influence breakdown phenomena.

A new model reproduces breakdown voltage and non-linear coefficient.

Non-linear I-V characteristics are explained by grain boundary properties.

Abstract

An attempt to determine theoretically the highly non-linear current-voltage (I-V) characteristics of polycrystalline semiconductors, such as ZnO-based varistors, is made from the electrical properties of individual grain boundaries under dc bias. The role played by the fluctuations of double Schottky barrier heights at grain interfaces on driving electrical breakdown phenomena of macroscopic samples is pointed out in terms of a binary mixture model. An alternative trial form for the double Schottky barrier height is introduced to reproduce the breakdown voltage as well as the high non-linear coefficient alpha, where I propto V^{alpha}. ------------- Copies upon request to: canessae@itsictp.bitnet