Structural optimization of silicon thin film for thermoelectric materials

The method to optimize nanostructures of silicon thin films as thermoelectric materials is developed. The simulated annealing method is utilized for predicting the optimized structure. The mean free path and thermal conductivity of thin films, which are the objective function of optimization, is evaluated by using phonon transport simulations and lattice dynamics calculations. In small systems composed of square lattices, the simulated annealing method successfully predicts optimized structure corroborated by an exhaustive search. This fact indicates that the simulated annealing method is an effective tool for optimizing nanostructured thin films as thermoelectric materials.

Analysis, Modeling, and Simulation of Thin-Film Cells-Based Photovoltaic Generator Combined with Multilayer Thermoelectric Generator

A new model for a multi-stage thermoelectric generator (TEG) is developed. An electrical and thermal model is built and simulated for different configurations of photovoltaic (PV) stand-alone hybrid systems, combining different stages of a TEG. The approach is evaluated with and without cooling by coupling a cold plate to a multi-stage hybrid PVTEG system. The model can be adjusted by sizing and specifying the influence of stage number on the overall produced power. Amorphous silicon thin-film (a-Si) is less affected by rising temperature compared to other technology. Hence, it was chosen for evaluating the lower limit gain in a hybrid system under various ambient temperatures and irradiances. The dynamics of the PVTEG system are presented under different coolant water flow rates. Finally, comparative electrical efficiency in reference to PV stand-alone was found to be for PVTEG without cooling, for PVTEG, and for multi-stage PVTEG, accordingly installing multi-stage PVTEG at Israel in a typical year with an average PV yield of generates an extra per module hence avoiding fossil energy and equivalent emissions.

The Effect of Temperature Variance with Different Surface Shapes on Efficiency of Silicon Thin Film Solar Cell

In this work, the temperature effects on the PV’s electrical and optical parameters of different surface gratings are studied. A 3D simulation is introduced for studying the PV’s electrical parameters such as short circuit current, open circuit voltage and efficiency at different levels of temperature with and without surface’s gratings. We observed that the efficiency is increased for PV of surface grating by about 4.87% compared to the free grating surface’s PV. The efficiency of the PV efficiency is degraded as we increased the temperature above 300K. The solar cell efficiency of gratings free is aggressively degraded compared to the solar cell that includes gratings by about 4.89% at 360K. The electrical parameters such as the open circuit voltage and short circuit current are enhanced compared to the PV of surface grating free. Also, we observed that the triangle grating geometry of dimensions about 10×10 nm produced a higher efficiency compared to the other PV of other grating geometries of same dimensions.