Long-range potential fluctuations and 1/f noise in hydrogenated amorphous silicon

TL;DR

This paper develops a microscopic theory linking 1/f voltage noise in hydrogenated amorphous silicon to long-range Coulomb potential fluctuations caused by deep defects, with predictions matching experimental data.

Contribution

It introduces a novel microscopic model that explains 1/f noise in amorphous silicon based on defect-induced Coulomb potential fluctuations.

Findings

The theory accurately predicts noise intensity and temperature dependence.

Experimental results agree well with theoretical predictions.

Long-range Coulomb fluctuations are key to understanding 1/f noise in this material.

Abstract

We present a microscopic theory of the low-frequency voltage noise (known as "1/f" noise) in micrometer-thick films of hydrogenated amorphous silicon. This theory traces the noise back to the long-range fluctuations of the Coulomb potential produced by deep defects, thereby predicting the absolute noise intensity as a function of the distribution of defect activation energies. The predictions of this theory are in very good agreement with our own experiments in terms of both the absolute intensity and the temperature dependence of the noise spectra.