Low Temperature Investigation of Electrical Conduction in Polysilicon: Simulation and Experiment

TL;DR

This study combines Monte Carlo simulations and electrical measurements to explore how temperature and voltage influence Coulomb oscillations in polysilicon nanowires with nanograins, revealing optimal conditions for oscillation visibility.

Contribution

It provides new insights into temperature-dependent electrical conduction and Coulomb oscillations in polysilicon nanowires, supported by both experimental data and simulations.

Findings

Irregular Coulomb oscillations observed below 200K

Enhanced oscillations at 25K-150K and high voltages

Simulations confirm experimental temperature and voltage effects

Abstract

Investigation of electrical conduction in polysilicon nanowires (polySiNW) with nanograins (5 to 20nm), based on Monte Carlo (MC) simulations and electrical measurements from 4K to 300K are presented. Some irregular Coulomb Oscillations (CO) are observed at temperatures lower than 200K showing several period widths due to the random distribution in grain size (5-20nm). A remarkable result consists in more effective oscillations observed at intermediate range of temperatures (between 25K and 150K) and high drain voltages. The temperature dependence of COs is explained by the fact that in a multiple asymmetric dot system at low temperature, COs are observed not at the lowest but at an intermediate temperature range, whereas the drain voltage dependence is due to an enhanced non-resonant tunneling. MC simulations have confirmed experimental observations.