Diode production by evaporating ag wi̇th cold substrate method on ZnO thin films grown vi̇a Sol-gel method andcharacterization

In recent years, ZnO thin films have been extensively used in piezoelectric, optoelectronic devices and photovoltaic cells. In this study, ZnO thin films were grown on glass and SnO2 substrate by using Sol-gel method and rotating coating technique, a simple, low cost and high controlled a way. Again, Schottky diode was produced with the PVD cold pad method on ZnO thin film which was optimized by evaporating Ag at two different temperatures such as 200K (cold bottom) and 300K. The obtained thin films and Schottky diodes were characterized by XRD, SEM, Optical and Electrical measurements. From the XRD measurements, the peaks of ZnO (002), (100), and (101) were found to be at 2θ (31.77), (34.42) and (36.25) angles, respectively. The average particle size of the films is calculated as 25 nm. The optical transmittance of the films was found to be greater than 95% and the ZnO energy band values of the films coated on different substrates were calculated to be around 3.25-3.35 eV. Peaks of various types of defects were observed in different wavelengths from photoluminescence measurements. The barrier height and ideal factor values of Ag/ZnO Schottky diodes at 200K and 300K were found as 0.43eV; 15.60 and 0.15eV; 7.41 respectively. The series resistance values were obtained as 4.46Ω; 4.88Ω and 3.65Ω; 4.78Ω from two different methods, respectively. Carrier concentration from the C-2-V curve for 200K and 300K was found to be 6.06 × 1016cm-3 and 4.05 × 1019cm-3 and Built-in Potentials (Vbi) was obtained as 0.55V and 0.70V, respectively. The ZnO resistivity was found to be 3,939 × 103Ω.cm. As a result, 15 of the diodes produced in 200K showed characteristics of the diode, whereas this number is 5 diodes for 300K.