Bandgap Narrowing Due to Heavy Doping in Si1-xGex Layers

In this work the bandgap narrowing due to heavy doping in SiGe alloys is calculated using first-order models at T=OK. A detailed overview of the way we have proceeded is given as well as a clarification of the different assumptions. Results are presented for n and p type doping, indicating that the values for the bandgap narrowing are approximately the same. We have also tried to extend this model for the case of strained SiGe layers. We found that the influence of the strain is rather small for p type layers, but is substantial for n type layers.