Abstract
Ga doped Zn0.85Ca0.15O thin films were prepared by spray pyrolysis method and studied the impact of Ga doping concentration on the physical properties of these films. XRD analysis confirmed the structural purity and polycrystalline nature of the films and composition analysis verified the incorporation of dopants in the structures. Optical transmission in the visible range initially increased and at higher Ga concentration decreased in accordance with the crystalline quality. Energy gap increased with doping percentage due to Burstein-Moss effect arising from the increase in carrier concentration. Ga doping resulted in enhanced electron concentration and consequently obtained lower resistive n type thin films. At higher doping level, electron density decreased due to the limit of solid solubility and hence conductivity slightly decreased but energy gap increased due to the extended localization arising from the poor crystallinity. Mobility decreased with doping due to the increased ionized impurity scattering at lower dopant concentration and due to intra-grain cluster scattering at heavy doping.
Highlights
Transparent and conducting oxides (TCOs) are an unparalleled class of materials which have been undergoing serious research for the last few decades
Glass substrates were cleaned with diluted chromic acid, sodium hydroxide solution and acetone followed by ultrasonic bath cleaning in hot distilled water. 15% Ca2+ substituted zinc oxide (ZnO) thin films were prepared with 0.4M aqueous solutions of zinc acetate dihydrate [Zn(CH3COO)2. 2H2O] and calcium acetate monohydrate [Ca(CH3COO)[2]
X-ray diffraction (XRD) pattern revealed the polycrystalline character of the films and conformed to hexagonal wurtzite structure without showing any trace of impurity phases such as Ga2O3, CaO etc. owing to the incorporation of both dopants in the ZnO lattice (JCPDS 36-1451)
Summary
Transparent and conducting oxides (TCOs) are an unparalleled class of materials which have been undergoing serious research for the last few decades. TCOs found immense applications in electronics and optoelectronics such as flat panel displays, light emitting diodes (LEDs), window defrosters, thin film solar cells, surface acoustic wave (SAW) devices, thin film transistors, etc.[1,2,3,4,5,6] In the beginning, indium oxide (In2O3) had been widely used in various TCO applications. Later on it was discarded due to its scarcity and replaced by the low cost, abundant, less toxic and biocompatible zinc oxide (ZnO). ZnO is a wide band gap semiconducting material (~3.37 eV). It exhibits better piezoelectric properties and possesses large free exciton binding energy (~60 meV) at room temperature
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
