THE INFLENCE OF ELECTRON BARRIER HEIGHT AT ELECTRODE ON ELECTRON TRANSPORT IN NEW DEVICE

Abstract

The influence of electronic barrier heights on the quantity of injection charge and electroluminescence (EL) in newly designed devices have been studied. By sandwithing Y2O3, ZnO thin films in between ITO and SiO or Al and ITO, we could change the electron barrier height and the quantities of the injection charges. It is found that Y2O3 film is a good electron barrier film, we sandwithed it in between Al and SiO layers and between ITO and SiO, respectively, and measured the injection charges data with different applied volotage. Using the Fowler-Nordeim tunneling current equation, the electron barrier height at SiO/Al 3.0 eV and at SiO/ITO 1.85 eV were obtained. The ZnO is a conducting film, the electron barrier height were reduced if sandwith it between Al and SiO layers or between ITO and SiO layers, by using the same method, we obtained the electron barrier height at ZnO/SiO, which is 0. 5 eV. The EL intensities of above devices have been measured and found that increasing the quantities of injection charges may increase the EL intensities in these new devices.