Fabrication and Characterization of GaN-Based Blue Light-Emitting Diode with Electrodes Formed by Screen Printing

We fabricated Ag electrodes on GaN-based blue light-emitting diodes (LEDs) by direct screen printing with Ag nanoparticle paste instead of commonly used dry processes. After the direct screen printing of Ag nanoparticle pastes on p-type GaN, successive sintering was carried out at 450°C for 30 min. LEDs with a square electrode size of 0.5 mm showed a threshold and operating voltage of 3.3 and 4.4 V, respectively. The maximum emission efficiency was obtained at 13 mA. These results suggest that screen printed Ag electrodes have a potential for use in GaN-based blue LEDs.