Break-Junction Tunneling Spectroscopy for Doped Semiconductors in the Hopping Regime

TL;DR

This paper develops a theoretical framework for tunneling spectroscopy in doped semiconductors exhibiting hopping conduction, emphasizing the conditions under which spectroscopic information can be accurately extracted from break-junction devices.

Contribution

It introduces a new theoretical model for break-junction tunneling in hopping regimes, addressing limitations of percolation methods and clarifying the scale interplay for spectroscopic analysis.

Findings

Derived an expression for the break-junction tunnel current in hopping semiconductors.

Highlighted the inadequacy of percolation methods for high tunnel resistance scenarios.

Discussed conditions for successful spectroscopic measurements in these devices.

Abstract

We present a theory for tunneling spectroscopy in a break-junction semiconductor device for materials in which the electronic conduction mechanism is hopping transport. Starting from the conventional expression for the hopping current we develop an expression for the break-junction tunnel current for the case in which the tunnel resistance is much larger than the effective single-hop resistances. We argue that percolation like methods are inadequate for this case and discuss in detail the interplay of the relevant scales that control the possibility to extract spectroscopic information from the characteristic of the device.