1/f Tunnel Current Noise through Si-bound Alkyl Monolayers

TL;DR

This paper investigates low-frequency 1/f tunnel current noise in Si-bound alkyl monolayer junctions, revealing bias-dependent noise features and proposing a model for trap-induced tunneling effects.

Contribution

It provides the first detailed analysis of 1/f noise in organic monolayer tunnel junctions and introduces a model explaining trap-related noise behavior.

Findings

1/f noise spectrum observed with power-law index between 1 and 1.2.

Bias-dependent increase in noise amplitude at V > 0.4 V.

Proposed model shows qualitative agreement with experimental data.

Abstract

We report low frequency tunnel current noise characteristics of an organic monolayer tunnel junction. The measured devices, n-Si/alkyl chain (C18H37)/Al junctions, exhibit a clear 1/ f γ power spectrum noise with 1< γ <1.2. We observe a slight bias-dependent background of the normalized current noise power spectrum (SI/I^2). However, a local increase is also observed over a certain bias range, mainly if V > 0.4 V, with an amplitude varying from device to device. We attribute this effect to an energy-dependent trap-induced tunnel current. We find that the background noise, SI, scales with >. A model is proposed showing qualitative agreements with our experimental data.