Pulsed laser deposition of thin films on actively cooled substrates

The paper deals with a special arrangement of pulsed laser deposition (PLD) when the substrates were cooled at cryogenic temperatures by liquid nitrogen during the deposition process. Applied materials – zinc oxide and titanium dioxide – play an important role in current optoelectronics and sensor research and a comparative study of their behaviour in presented PLD arrangements were performed.Prepared films (deposited on different substrates: Si (100) and sapphire) were investigated in as-deposited states and their properties in dependence of deposition temperature were compared. Investigation by X-ray diffraction and Raman spectroscopy proved their amorphous structure. Subsequently, annealing under different temperatures (up to 800 °C) was applied and properties of modified structures were compared by using different analytical methods (scanning electron microscopy, X-ray diffraction, Raman spectroscopy, optical absorption spectroscopy and spectroscopic ellipsometry).Pulsed laser deposition with cryogenic cooling of substrates opens a promising way for deposition of materials in non-equilibrium state. Such structures differ significantly between their counterparts despite of identical chemical composition. Annealing of such amorphous structures provide special conditions for studying of their recrystallization dynamics and controlling of their properties.

► Pulsed laser deposition on cooled substrates. ► Deposition of ZnO and TiO2 thin films. ► Comparison of results in dependence of deposition temperature. ► Amorphous structures of applied materials were successfully achieved. ► Annealing transformed amorphous structures to crystalline.