Quantum size effect simulation and Ge composition on SiGe quantum dot for intermediate band solar cell applications

The influence of the Ge composition for SiGe quantum dot structures and the influence of dot-size in some intermediate band solar cell properties have been simulated. The variations of Ge compositions ranging from 0% to 100% and variations of quantum dot sizes ranging from 1 to 5 nm were applied in these simulations. An addition of Ge to Silicon quantum dot found to be effective to increase the generation rate of charge carriers. Simulation results show that if there is a decrease in the composition of Germanium in SiGe quantum dot, there will be an increase in the absorption coefficient of material. This will eventually cause an increase in the generation rate. A higher Ge composition and a bigger quantum dot size will result into a wider range of wavelength where a pair of electron and hole can be generated.