In this laboratory experiment, we applied zinc oxide (ZnO) in solution to indium tin oxide (ITO) and then dried the ZnO into a film to form an electric device. Using a two " point probe, we induced a voltage drop across the ZnO-ITO interface. From this potential, we measured the current in order to determine the resistances using a quadratic fit to Ohm's Law that we used in Labview. Based upon the thickness of the ZnO film on the ITO, different current values were obtained and allowed for comparison of this device to a diode or rectifying component. We plotted the IV curves of the ZnO-ITO using the data from several tests we ran. .
Introduction .
Last semester, we synthesized 10 nm Zince Oxide nanoparticles in order to study its crystal structure and particle size. ZnO, however, is synthesized widely in the materials science field to be utilized for its electric properties, namely in optoelectronics. Because there is a difference in electron affinities between ITO and ZnO, a semiconductor interface is formed. The ZnO acts as an electron donor because it has a larger electron affinity, and ITO acts as an electron acceptor, or hole donor, because of the lower electron affinity. In this experiment we prepared our own ZnO-ITO device by depositing ZnO nanoparticles in solution onto ITO glass and evaporating the solvent. Using a multimeter, we altered the voltage drop across the ZnO-ITO interface, which allows us to measure the induced current that flows through the devices. We then recorded the results to make the current verses voltage (IT) curves. From this curve we can calculate the resistance (the slope of the IV curve) specific to the area and the thickness of the film using ohms law if needed. .
V = I * R .
V is the voltage in Volts, I is the current in Amps, and R is the resistance in Ohms. The IV curves in this experiment, however, are not linear and behave on a quadratic fit of Ohms law.
