Optoelectrical Properties of NiInZnO (NIZO) Thin Films
K. Mensah-Darkwa1, A. Dere2, Abdullah G. Al-Sehemi3-5, Ahmed A. Al-Ghamdi6, Ram K. Gupta7,* and F. Yakuphanoglu2,8,*
1Department of Materials Engineering, College of Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
2Firat University, Nanoscience and Technology Laboratory, Elazig, Turkey
3Department of Chemistry, Faculty of Science, King Khalid University, Abha 61413, P.O. Box 9004, Saudi Arabia
4Research Center for Advanced Materials Science, King Khalid University, Abha 61413, P.O. Box 9004, Saudi Arabia
5Unit of Science and Technology, Faculty of Science, King Khalid University, Abha 61413,P.O. Box 9004, Saudi Arabia
6Department of Physics, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia
7 Department of Chemistry, Pittsburg State University, Pittsburg, KS 66762, USA
8Department of Physics, Faculty of Science, Fırat University, Elazig, Turkey
Abstract: This report presents the fabrication and characterization of x % Ni – InZnO (NIZO) Schottky diodes. The structural, optical and electrical properties of the fabricate Al/p-Si / x % Ni – InZnO /Au photodiodes were investigated. An average visible transmittance of about 75% – 85% has been obtained in the visible-light to near-infrared wavelength region. The optical bandgap was 3.17 ± 0.02 eV. Current-Voltage measurements were conducted to analyze the photodiode behavior under dark and light illumination. The reverse bias current increases together with increasing light illumination. The observed I-V results confirm the photoconductive and photovoltaic properties of the fabricated diode. There is an exponential relationship between the current and the voltage in the forward bias, confirming the rectification performance of the photodiode. The electrical properties of the fabricated photodiodes were evaluated using Cheung- Cheung and Norde’s methods. The transient photocurrent, capacitance-voltage-frequency and conductance-voltagefrequency plots indicate that the diode is very sensitive to light illumination. We also observe a strong correlation between capacitance and conductance on frequency, this was explained based on the presence of interface states. The obtained results suggest that the Ni-doped InZnO photodiodes can be useful in photovoltaic and optoelectronic applications.
Keywords: Ideality factor, bandgap, InZnO, photodiode, Optoelectrical.