Tight binding modeling of band gaps and band offsets in heterostructures H. Hakan Gu ¨rel a ,O ¨ zden Akıncı a , Hilmi U ¨ nlu ¨ a,b, * a Computational Science and Engineering Division, Informatics Institute, _ I stanbul Technical University, Maslak 80626, _ I stanbul, Turkey b Department of Physics, Faculty of Science and Letters, _ I stanbul Technical University, Maslak 80626, _ I stanbul, Turkey Abstract Advances in growing semiconductor thin films with different physical and chemical properties has provided new opportunities in basic science studies and device applications in the electronics industry. Realization of the full poten- tials of heterostructures for novel nanoscale semiconductor devices require reliable and precise predictive models that are consistent with the fundamental principles of solid state physics. In this article, we present a semi-empirical second nearest neighbor sp 3 tight binding view of heterostructure electronic band structure calculations. Using this scheme, we discuss the modeling of the electronic band structure of AlGaAs/GaAs and InGaAs/GaAs heterostructures. The model should be useful in understanding the effects of electronic structure of heterostructures on charge transport and perfor- mance of nanoscale devices. Ó 2005 Elsevier B.V. All rights reserved. Keywords: Modeling; Tight binding theory; Heterostructures; Nanoelectronics 1. Introduction Advancement in the nanoscale heterostructure semiconductor device technologies requires reli- able and precise predictive process and perfor- mance simulation models. As with all of the semiconductor devices, the key property to under- stand the impact of heterostructure on the device performance is the electronic energy band struc- ture across the interface. When the semiconductor composition changes abruptly at interface between constituents, the difference in their energy bands is accommodated by the discontinuities in the con- duction and valence bands. The spike DE c in the conduction band and step DE v in the valence band at heterointerface influences the carrier transport and in turn influence the device performance and reliability [1–6]. Consequently, theoretical studies 0927-0256/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.commatsci.2004.12.047 * Corresponding author. Present address. Department of Physics, Faculty of Science and Letters, _ Istanbul Technical University, Maslak 80626, _ Istanbul, Turkey. Tel.: +90 212 285 3201; fax: +90 212 285 6386. E-mail address: hunlu@itu.edu.tr (H. U ¨ nlu ¨). Computational Materials Science 33 (2005) 269–275 www.elsevier.com/locate/commatsci