Ion implantation induced phase transformation and enhanced crystallinity of as deposited copper oxide thin films by pulsed laser deposition

• Thin films of copper oxide deposited by pulsed laser deposition at 350 °C.
• Amorphous copper oxide transformed to crystalline Cu2O phase by low energy ion implantation.
• Mixed copper oxide phases transformed to single phase of Cu2O by ion implantation.
• Sheet resistance decreased with particle fluence.

Copper oxide thin film of about 260–280 nm thickness was deposited using pulsed laser deposition (PLD) on glass substrate at 350 °C and post depositional sample treatment was performed by ion implantation with 50 keV N5+ ion beam with varying particle fluence. Amorphous copper oxide thin film deposited at 80 mTorr partial pressure of oxygen was transformed to cubic Cu2O phase (20.2 nm) when implanted at 1 × 1016 particles/cm2. While mixed Cu2O and CuO phases in the thin film deposited at 100 mTorr oxygen pressure was transformed to single phase of Cu2O (23.5 nm), with enhanced crystallinity when implanted with 2.5 × 1015 particles/cm2. The phase transformation and improved crystallinity is attributed to thermal effect owing to stopping of incident ion beam. Implantation with higher particle fluence led to transformation to CuO phase with reduced crystallite sized and the increased electrical conductivity.