GaAs heterojunction devices with MDMO-PPV thin films

Au/MDMO-PPV/n-GaAs heterojunction devices were fabricated. The electronic properties of these devices were investigated at room temperature. The I-V characteristics of Au/MDMO-PPV/n-GaAs heterojunction devices show rectification behavior. The important diode parameters such as series resistance (Rs), ideality factor (n) and barrier height (BH) were determined by performing different plots from the forward bias ln I-V, Cheung and Norde plots. It is seen that there is not an agreement between the values of the junction parameters obtained from these methods. The thin film of MDMO-PPV was introduced as an efficient interlayer for achieving modification of the interfacial potential barrier of metal/n-GaAs diode. Also, the MDMO-PPV thin films have been prepared by spin coating on glass substrate. The obtained films have been characterized by ultraviolet-vis (UV-vis) spectroscopy. UV-vis absorption measurements indicate that the band gap of MDMO-PPV film is 2.20 eV.