promoting access to White Rose research papers White Rose Research Online Universities of Leeds, Sheffield and York http://eprints.whiterose.ac.uk/ This is an author produced version of a paper published in Applied Physics Letters. White Rose Research Online URL for this paper: http://eprints.whiterose.ac.uk/3632/ Published paper Lever, L., Valavanis, A., Ikonic, Z. and Kelsall, R. W. (2008) Simulated [111] Si- SiGe terahertz quantum cascade laser. Applied Physics Letters, 92 (2). 021124. doi: 10.1063/1.2836023 eprints@whiterose.ac.uk