Modeling and Control of Thin Film Surface Morphology: Application to Thin Film Solar Cells.

摘要

Thin film solar cells, which consist of multiple layers such as the PIN layers and the Transparent Conducting Oxide (TCO) layers, are playing a more and more important role in the overall solar cell market owing to the potential of improving light conversion efficiencies (currently on the order of 10;This dissertation presents a systematic framework for modeling and control of thin film surface morphology in both PIN layers and TCO layers. Specifically, we will present novel definitions for describing surface morphology by introducing both the surface root mean square roughness and slope to describe the surface morphology, study its physical properties and dependence on model parameters such like lattice size, activation energies and temperature, introduce and identify stochastic closed-form equations describing surface morphology, and finally design model predictive controllers to control the surface morphology to desired levels. Extensive simulation results are presented to demonstrate the effectiveness of the proposed modeling and control framework.