The Efficacy of the Method of Four Coefficients to Determine Charge Carrier Scattering

TL;DR

This paper introduces the method of four coefficients, incorporating Nernst coefficient measurements, to more accurately determine charge carrier properties in semiconductors, addressing limitations of traditional methods.

Contribution

It presents a novel approach that includes the Nernst coefficient in transport analysis, improving the accuracy of extracting electronic properties from measurements.

Findings

The method maps the full solution sub-space for carrier properties.

Nernst coefficient measurements resolve uncertainties in traditional analysis.

Sensitivity analysis shows robustness of the method to experimental errors.

Abstract

The investigation of the electronic properties of semiconductors is inherently challenging due to the ensemble averaging of fundamentals to transport measurements (i.e., resistivity, Hall, and Seebeck coefficient measurements). Here, we investigate the incorporation of a fourth measurement of electronic transport, the Nernst coefficient, into the analysis, termed the method of four-coefficients. This approach yields the Fermi level, effective mass, scattering exponent, and relaxation time. We begin with a review of the underlying mathematics and investigate the mapping between the four-dimensional material property and transport coefficient spaces. We then investigate how the traditional single parabolic band method yields a single, potentially incorrect point on the solution sub-space. This uncertainty can be resolved through Nernst coefficient measurements and we map the span of the ensuing sub-space. We conclude with an investigation of how sensitive the analysis of transport coefficients is to experimental error for different sample types.