Applications of laser plasma deposition

摘要

Summary form only given. Laser plasma deposition or Pulsed laser deposition (PLD) is an attractive technique for growth of different materials for a variety of applications including thin films and nanostructures. The main advantage of using PLD for growth of materials is low cross contamination while controlling the stoichiometry of the material. Controlling the laser fluence, partial pressure of gas in the PLD chamber and substrate temperature can be used to change the material growth rate and crystal properties.Here we present our work for growth of different materials and nano-structures using PLD for applications ranging from thin film transistors (TFTs) to free-standing thin films which can be utilized for targets in laser matter interaction experiments. Growth of thin films of wide bandgap semiconductors like zinc oxide (ZnO) was optimized for high mobility and low doping density to fabricate TFTs. The optimized ZnO thin films, grown using a ns KrF laser, demonstrated a mobility as high as 15 V.cm2/s [1]. Nanowires were grown using Glancing Angle Pulsed Laser Deposition technique [2]. Nanodots were grown using both ns KrF and fs Ti-sapphire laser. E-beam lithography mask was also used to grow uniform sized nanodot arrays of various materials like Si, Ge, ZnO and GaAs [3]. These nanodots can be utilized for different applications like solar cells, LEDs, sensors, etc. We have also utilized PLD for growth of free-standing thin films of diamond like carbon (DLC) for high intensity laser plasma experiments. These DLC free-standing films demonstrate damage threshold as high as 7x1010 W/cm2 [4]. Thin metal films with large crystalline sizes are also being grown as freestanding targets in experiments using ultrafast electron diffraction to probe laser produced warm dense matter. The results from all these studies will be presented to demonstrate the various applications of laser plasma deposition technique.