Methods for magnetotransport characterization of IR detector materials

Abstract

Advanced techniques for the magnetotransport characterization of semiconductor IR detector materials are reviewed. Both conventional mixed-conduction and 'mobility spectrum' analyses of the resistivity tensor as a function of magnetic field and temperature are discussed, as well as a hybrid approach which exploits the advantages of both methods. Assuming that the data are sufficiently sensitive, one obtains concentrations and mobilities for each electron and hole species present in a given sample. This is particularly valuable for narrow-gap infrared detector materials such as Hg,,Cd,Te, since the coexistence of multiple species tends to be the rule rather than the exception, and 'anomalous' Hall data are easily misinterpreted if inferences are drawn from measurements at only a single magnetic field. In addition to bulk electron and hole densities and mobilities, one can determine inversion and accumulation layer properties from the anomalous Hall effect, acceptor binding energies and compensation ratios from the low-temperature freeze-out of free holes, and energy gaps from the temperature dependence of the intrinsic carrier concentration. Shubnikov-de Haas and quantum Hall measurements provide additional information about the spatial distribution of the carriers. Electron and hole mobilities in Hg,,Cd,Te detector materials will be briefly reviewed, and theoretical and experimental results compared

Demonstration of nearly non‐degenerate electron conduction in InN grown by molecular beam epitaxy

“…[2,3] The results of the present study indicate that variable-field Hall techniques are very useful for evaluating multiple carrier transport in InN epilayers, as well as distinguishing strongly n-type material near the interface from the higher quality, and potentially non-degenerate, material near the surface.…”

“…[7,8] It should be noted that QMSA does not depend on any a priori assumptions about the type and number of carriers, and can actually reveal information about potential non-uniformity, or spread, in mobility for a given carrier.…”

Scattering analysis of two-dimensional electrons in AlGaN/GaN with bulk related parameters extracted by simple parallel conduction extraction method

“…The analysis of Hall data for the parallel conduction problem have been discussed in many papers with using the methods like: two-carrier model, 14 multicarrier fitting procedure ͑MCF͒, 15 mobility-spectrum analysis ͑MSA͒, 16 MCF and MSA hybrid, 17 and the QMSA. 11,12 All these methods have advantages and disadvantages over each other depending on the individual problem that they address.…”

Extraction and scattering analyses of 2D and bulk carriers in epitaxial graphene-on-SiC structure

“…For the analysis of the Hall data with a parallel conduction problem, several methods are proposed or reported in the literature, such as the two-carrier model [11], multi carrier fitting procedure (MCF) [12], mobility-spectrum analysis (MSA) [13], a MCF and MSA hybrid [14], the quantitative mobility spectrum analysis [15,16], and the maximum entropy mobility spectrum analysis [17]. All these methods have advantages and disadvantages for solving parallel conduction problem of different systems.…”