Effect of titanium-dioxide nanoparticle on Richardson constant and barrier height of tartrazine dye based Schottky device

Abstract

Abstract Recently Fruit Dyes have achieved a significant interest as organic devices because of they are widely available, customizable and biodegradable. But low conductivity is one of the major limitations. Low conductivity is due to low charge injection from the electrodes to the organic layer and the charge injection process is strongly dependent on the injection barrier height at the metal-dye interface. Higher barrier height causes low charge injection. A detailed analysis is needed to reduce the interfacial barrier to get better conductivity. In this work, we have estimated the interfacial barrier height of Indium tin oxide coated glass/Tartrazine dye/Copper based device with and without titanium dioxide nanoparticles. The devices have been prepared with dye and dye-nanoparticles blends by using the spin coating technique. We have measured the steady state dark current–voltage–temperature characteristics in the range of 288 K to 333 K to estimate the Richardson constant and interfacial barrier height. The Richardson constant was found to be modified from 44.35 × 10–3 to 07.34 × 10–3 Am−2 K−2. We also have found that interfacial barrier height is reduced from 0.71 eV to 0.64 eV in the presence of nanoparticles at room temperature. As the temperature increased, the interfacial barrier height increased to 0.72 eV from 0.71 eV and to 0.68 eV from 0.62 eV for dye based device with and without nanoparticles, respectively. Reduction of the interfacial barrier height indicates an increase in the charge injection through the interface. This work will be informative to improve the charge flow at the metal–fruit dye interface.

Keywords

• Natural dye
• Titanium-dioxide nanoparticle
• Schottky contact
• Richardson constant