Abstract
We report on room temperature diode characteristics of ZnO:Al (AZO)/Si heterostructures by current-voltage measurements. In this study, with increasing AZO film thickness, systematic reduction in the turn-on potential (from 3.16 to 1.80 V) and the film stress are observed. Complementary capacitance-voltage studies reveal a decreasing trend in barrier height at the junction with increasing AZO film thickness. A gradual decrease in resistivity takes place with increasing AZO film thickness. Above observations are explained in the framework of AZO thickness dependent variation in grain size and in turn trap density at the grain boundaries influencing carrier transport across the adjacent grains.
Highlights
ZnO is a good candidate for fabricating solar cells,[1] heterojunction diodes,[2] and photodetectors[3] due to its wide band gap, Eg (∼3.3 eV), large binding energy (60 meV), and high transparency
We report on room temperature diode characteristics of ZnO:Al (AZO)/Si heterostructures by current-voltage measurements
In order to explain this behaviour, thickness dependent evolution of grains in the deposited AZO films was investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM), while their nature of crystallinity was examined by x-ray diffraction (XRD)
Summary
ZnO is a good candidate for fabricating solar cells,[1] heterojunction diodes,[2] and photodetectors[3] due to its wide band gap, Eg (∼3.3 eV), large binding energy (60 meV), and high transparency. Doping of group III elements in ZnO films[4] (especially Al-doping) has generated considerable interest. They are important for different applications including fabrication of transparent conductive oxide[1,5,6] and from the fundamental standpoints. Within a moderate Al-doping, it is known that the broadening of Eg is associated with partial filling of states above the conduction band minimum of AZO – known as BursteinMoss effect,[8] whereas the carrier concentration above the Mott critical density is known to be associated with decreasing Eg due to the modification of the bands through electron-electron and electron-impurity interactions.[9] Different techniques have been employed so far to synthesize AZO films, which includes pulsed laser deposition,[5] chemical processing,[10] direct current (dc) sputtering,[8] etc. In order to explain this behaviour, thickness dependent evolution of grains in the deposited AZO films was investigated by atomic force microscopy (AFM) and scanning electron microscopy (SEM), while their nature of crystallinity was examined by x-ray diffraction (XRD)
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.
