Design and characterization of transparent thin film nanostructure device

Indium tin oxide (ITO) is one of the most widely used transparent conducting oxides (TCO) because of its electrical conductivity and optical transparency.We have grown ``all oxide'' transparent $p-n$ junction thin film nanostructure device by using chemical solution deposition and e-beam evaporation onto SiO$_{2}$ substrate. The oxide $p-n$ junction was characterized by GIXRD, AFM, UV-Vis. spectroscopy and I-V measurements. Combined GIXRD and AFM confirm phase pure, mono-disperse 30 nm NiO and ITO nanocrystallites. More than 70{\%} optical transparency is achieved across 160 nm thick $p-n$ junction. The forward bias current is greater than the reverse bias current by approximately a factor of 10$^{4}$ in the measured voltage s weeping range. A small leakage current as low as 12 nA was observed at a reverse bias of --5 V. Previously, Tonooka and co-authors [3] reported the average turn on voltage of their n-ZnO / p-Cu-Al-O diode $\sim $ 0.5 V, which is higher than our $p$-NiO/$n$-ITO diode. This is mainly because of the large variations in the carrier concentrations as well as larger lattice mismatch between the oxides forming the $p-n$ junction. The observed optical and electrical properties of oxide transparent diode are attributed to the heteroepitaxial nature and carrier diffusion at the junction interface.