Validating surface evolution modeling on high temperature selective emitters : an investigation of the thermal stability of nano-scale surface structures for thermophotovoltaic systems

Abstract

As the world's traditional energy sources come under scrutiny due to dwindling supply and negative environmental impact, a global effort is being made into alternative energy systems. One such system involves the use of thermophotovoltaics (TPV), which convert thermal energy to electricity. Nano-patterned features can im prove electromagnetic emission from the TPV emitter, increasing system efficiency. These features, however, degrade at high temperatures over tine. One of the main contributors to surface evolution is surface diffusion. This investigation tested surface diffusion based simulation modeling, comparing computational results with experimental findings for high temperature annealed silicon, a cost effective material for testing instead of tungsten. Although the simulation model fits within 25% of the post-annealed curvature caused by surface diffusion, discrepancies in the simulation's time scale need to be addressed in future models for accurate time dependent modeling.