Principles of Monte-Carlo ray-tracing simulations of quantum dot solar concentrators

A tool for ray tracing simulations of quantum dot solar concentrators is developed on the basis of Monte-Carlo methods that are applied to polarization-dependent reflection/transmission at interfaces, photon absorption by the semiconductor nanocrystals and photoluminescent reemission. A real time three-dimensional representation of the beam trajectories provides the user with an immediate visual control of the optical behavior of the simulated system. The software allows importing measured or theoretical absorption/reemission spectra describing the photoluminescent properties of the quantum dots. Hereby the properties of photoluminescent reemission are described by a set of emission spectra depending on the energy of the incoming photon. The inverse function method is then used to simulate the photoluminescent emission according to the corresponding photon energy distribution. For quantum dot containing systems, the simulated and measured transmission spectra are matching closely. Simulated spectra of the concentrated radiation exhibit the redshift which is typical for planar photoluminescent concentrators.