Journal
SUPERLATTICES AND MICROSTRUCTURES
Volume 112, Issue -, Pages 654-664Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.spmi.2017.10.023
Keywords
Impedance spectroscopy; Cole-cole plot; Charge transport; Hybrid diode; Phthalocyanine; Mobility
Categories
Funding
- Ministry of Communications and Information Technology, Government of India [12(3)/2010-PDD]
Ask authors/readers for more resources
We report an investigation of the optoelectronic properties of a hybrid p-n diode device fabricated using ZnO film prepared by sol-gel technique on which a VOPc organic film is deposited by vacuum evaporation. The charge transport properties of devices having the configurations ITO/ZnO/Al and ITO/ZnO/VOPc/MoO3/Al were investigated at different annealing temperatures (150 degrees C, 250 degrees C, 350 degrees C and 450 degrees C) by Impedance Spectroscopy (IS). The structural, morphological, optical and electrical properties were also studied at different annealing temperatures. The parameters related to the ITO/ZnO and ZnO/VOPc interfaces such as ideality factor (n), barrier height (q phi(B)) and rectification ratio (RR) of the diodes were determined from current density-voltage U-V) characteristics. IS measurements suggest that the large photocurrent generated is due to the decrease in bulk resistance of the device on account of the generation of electron-hole pairs in the organic active layer when exposed to light. The RR and the photocurrent responsivity (R-ph) values obtained from the J-V characteristics compare well with those obtained from the IS measurements. It was observed that the absolute value of R-ph (470 mA/W) for the p-n diode with ZnO annealed at 350 degrees C is high compared to that of diodes with different ZnO annealing temperatures. These values also agree well with the values obtained for p-n diodes of other phthalocyanines. Our studies clearly demonstrate that a p-n diode with ZnO film annealed at 350 degrees C exhibits much better optoelectronic characteristics on account of increased grain size, improved charge injection due to the reduction of barrier height and hence higher (up to 5 orders) charge carrier mobility. (C) 2017 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available