| Title |
Electron Beam Evaporated ITO Transparent Electrode for Highly Efficiency GaN-based Light Emitting Diode |
| Authors |
서재원(Jae Won Seo); 오화섭(Hwa Sub Oh); 강기만(Ki Man Kang); 문성민(Seong Min Moon); 곽준섭(Joon Seop Kwak); 이국회(Kuk Hwe Lee); 이우현(Woo Hyun Lee); 박영호(Young Ho Park); 박해성(Hae Sung Park) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
ITO; ohmic contact; LED; electron beam evaporator |
| Abstract |
In order to develop transparent electrodes for high efficiency GaN-based light emitting diodes (LEDs), the electrical and optical properties of the electron beam evaporated ITO contacts have been investigated as a function of the deposition temperature and flow rate of oxygen during the deposition. As the deposition temperature increases from 140℃ to 220℃, the resistivity of the ITO films decreases slightly from 4.0×10-4 Ωcm to 3.3×10-4 Ωcm, meanwhile the transmittance of the ITO films significantly increases from 67% to 88% at the wavelength of 470 nm. When the flow rate of oxygen during the deposition increases from 2 sccm to 4 sccm, the resistivity of the ITO films increases from 3.6×10-4 Ωcm to 7.4×10-4 Ωcm, meanwhile the transmittance of the ITO films increases from 86% to 99% at 470 nm. Blue LEDs fabricated with the electron beam evaporated ITO electrode show that the ITO films deposited at 200℃ and 3 sccm of the oxygen flow rate give a low forward-bias voltage of 3.55 V at injection current of 20 mA with a highest output power. |