Princeton University

School of Engineering & Applied Science

A Tale of Two Anisotropies: Transverse Thermoelectrics & 2D Electron Density Gradients

Professor Matthew Grayson, Northwestern University
Engineering Quadrangle, J401
Friday, September 12, 2014 - 10:00am

Anisotropic charge transport in semiconductors can be useful for devices as well as for diagnostics.  This talk will discuss two otherwise unrelated topics that both stem from exploiting anisotropic effects in semiconductors.  The first anisotropic material explored is a transverse thermoelectric whereby electric current drives perpendicular heat flow.  Such materials are termed (p x n)-type materials since they are dominated by p-type hole conduction along one axis and by n-type electron conduction in the transverse direction.  The second anisotropic system studied is a quantum well with an electron density gradient.  An analysis method is demonstrated whereby this electron density gradient can be quantified by measuring the longitudinal resistance at +B and -B magnetic field.