Conductivity modification of ZnO film by low energy Fe ion implantation

In this paper we report the structural, optical and electrical behaviours of ZnO films implanted with 300 keV Fe¹⁰⁺ ions. From UV-vis spectroscopy it is observed that the band gap of the films decreases after implantation. Photoluminescence yield seems to increase in the implanted samples. From Hall measurements it is observed that the unimplanted sample shows n-type conductivity for the entire temperature range (100-300 K), whereas after implantation the samples show p-type conductivity for ≤200 K. The DC resistivity of the implanted samples is found to be lower than that of the unimplanted sample. We have found that the magnetoresistance of our samples is positive in the temperature range 200-300 K, but it becomes negative below 200 K.