Computer Physics Communications 142 (2001) 274–280 www.elsevier.com/locate/cpc Electronic thermal transport and thermionic cooling in semiconductor multi-quantum-well structures B. Lough, S.P. Lee, R.A. Lewis, C. Zhang ∗ Institute for Superconducting and Electronic Materials, University ofWollongong, Wollongong, New South Wales 2522, Australia Abstract Recently, it has been proposed that semiconductor or metal-semiconductor multilayer systems can be used as energy generator or cooling devices based on the principles of thermionic emission. Such thermionic cooling devices will have much higher figures of merit than thermoelectric devices. Multilayer thermionic structures have advantages of reduced phonon transport and thus increased thermal efficiency. In this work we present a numerical investigation of the electronic thermal transport in multilayer systems. The figure of merit for different multilayer structures is calculated and optimized to give bias and temperature as a function of work function of the material. 2001 Elsevier Science B.V. All rights reserved. PACS: 72.20.Pa; 44.10.+i; 73.40.Sx Keywords: Thermionic cooling; Electron thermal transport; Multilayer structures 1. Introduction Semiconductor multi-quantum-well structures play an important role in the new generation of electronic and optoelectronic devices. Recently, the research in this area has been further expanded into the area of electronic thermal conduction in semiconductor multilayers and its application in solid-state power generation and refrigeration [1–6]. A new method of refrigeration has been recently described [2] which is based on thermionic emission in semiconductor multilayers. The generators and refrigerators based upon thermionic emission are efficient with their theoretical efficiency approaching the Carnot efficiency. In a recent work we have shown that the theoretical efficiency can be enhanced in an asymmetric device due to electron thermalization in the barrier region [7]. Fig. 1 shows a potential energy diagram for an electron between two metal surfaces with different work functions: φ 0 on the left which is cold with temperature T 0 , and φ 1 on the right which is hot with temperature T 1 >T 0 . We take the electron charge e> 0 and φ 0,1 > 0. The space between the surfaces is vacuum or filled with a dilute gas. Here the electric field is constant. The two horizontal lines represent the chemical potentials for the two metal plates, which serve as electrodes. * Corresponding author. E-mail address: c.zhang@uow.edu.au (C. Zhang). 0010-4655/01/$ – see front matter  2001 Elsevier Science B.V. All rights reserved. PII:S0010-4655(01)00345-9