I am doing research on tin and tin oxide nanoparticles using laser ablation method. Using Nd:YAG laser in visible range (532nm) .By increasing the energy i have absorbed an increase in bandgap. What might be the reason.
Dear Jafary, nonlinear grows of temperature with pulse energy absorbance is main reason of your observation. The phenomena has been studied well. I provide You some conclusion from review paper:"Absorptivity as a function of temperature is an important consideration in practice and is usually modelled successfully as a linear function except around the melting point of the metal where there is a significant jump due to the sudden change of conduction electron density".