Surface Band-Gap Narrowing in Quantized Electron Accumulation Layers

P. D. C. King, T. D. Veal, C. F. McConville, J. Zúñiga-Pérez, V. Muñoz-Sanjosé, M. Hopkinson, E. D. L. Rienks, M. Fuglsang Jensen, Ph. Hofmann
2010 Physical Review Letters  
An energy gap between the valence and the conduction band is the defining property of a semiconductor, and the gap size plays a crucial role in the design of semiconductor devices. We show that the presence of a two-dimensional electron gas near to the surface of a semiconductor can significantly alter the size of its band gap through many-body effects caused by its high electron density, resulting in a surface band gap that is much smaller than that in the bulk. Apart from reconciling a number
more » ... econciling a number of disparate previous experimental findings, the results suggest an entirely new route to spatially inhomogeneous bandgap engineering.
doi:10.1103/physrevlett.104.256803 pmid:20867408 fatcat:6nvlibifvffozmxunplerffeeu