Abstract
We demonstrate and detail a full anisotropic effective mass Density Functional Theory model of heavily P-doped Silicon quantum dots of arbitrary shape, and use it to calculate the electronic structure of isolated single and double Quantum Dot structures. The Finite Difference method is employed to solve the anisotropic effective mass Schrodinger equation, and also a novel solution of the Poisson equation with freespace boundary conditions. Results are given for both single and double dot structures with a demonstration of the effects of varying several geometric and electronic parameters. Typical dot parameters are 10 nm diameter, 10 nm tall, containing 50 free electrons and with 100 static electrons distributed along the oxidised surface. In varying the magnitude of a potential gradient along the inter-dot axis of IDQDs, we see two regimes of charge movement; a discrete regime where the orbitals are well confined to one dot and a continuous regime where there are orbitals delocalised occupying both dots or the the neck region. Thus we see the transition from one dot to two. Significant instability in the solution of the discrete regime is also discussed.