Self-powered p-NiO/n-ZnO heterojunction ultraviolet photodetectors fabricated on plastic substrates
Md Rezaul Hasan1, Ting Xie2, Sara C Barron3
1Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899 USA; Department of Electrical and Computer Engineering, George Mason University, 4400 University Drive, Fairfax, VA 22030, USA.
Abstract:
A self-powered ultraviolet (UV) photodetector (PD) based on p-NiO and n-ZnO was fabricated using low-temperature sputtering technique on indium doped tin oxide (ITO) coated plastic polyethylene terephthalate (PET) substrates. The p-n heterojunction showed very fast temporal photoresponse with excellent quantum efficiency of over 63% under UV illumination at an applied reverse bias of 1.2 V. The engineered ultrathin Ti/Au top metal contacts and UV transparent PET/ITO substrates allowed the PDs to be illuminated through either front or back side. Morphology, structural, chemical and optical properties of sputtered NiO and ZnO films were also investigated.


