Bottom-emission organic light-emitting diodes using semitransparent anode electrode by O2 plasma

• Published in: Organic electronics Vol. 13; no. 11; pp. 2594 - 2599
• Main Authors: Hyung, Gun Woo, Lee, Dong Hyung, Lee, Ho Won, Kim, You Hyun, Lee, Seok Jae, Koo, Ja Ryong, Kim, Woo Young, Kim, Young Kwan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.11.2012; Elsevier
• Subjects: Applied sciences; Bottom-emission organic light-emitting diodes (BEOLEDs); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electronics; Exact sciences and technology; Hole injection; Multi-metal thin-films; Nickel oxide; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Optoelectronic devices; Oxygen plasma; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Oxygen plasma; Hole injection; Multi-metal thin-films; Optical properties; Nickel oxide; Bottom-emission organic light-emitting diodes (BEOLEDs); Performance evaluation; Electron-hole recombination; Hole; Anode; Plasma assisted processing; Microcavity; Luminous efficiency; Thin film; Metallic thin films; Charge carrier recombination; Bottom emission; Optoelectronic device; Optical characteristic; diodes (BEOLEDs); Electrical characteristic; Organic electronics; Semitransparent material; Oxygen; Electrical properties; Indium; Quantum yield; Bottom-emission organic light-emitting; ulti-metal thin-films; Luminance; Flexible structure; Organic light emitting diodes; Nickel; Green light; Charge carrier injection
• ISSN: 1566-1199; 1878-5530
• DOI: 10.1016/j.orgel.2012.07.020

[Display omitted] ► A multi-metal stack of Ni/Ag/Ni are fabricated on a plastic substrate. ► The electrical and optical characteristics were efficiently enhanced by O2 plasma. ► Our OLED exhibits a 14,280cd/m2, 8.5cd/A, 2.6%, and (0.32, 0.58) on PET substrate. ► We introduce an ITO-free structure produced on PET substrate by a simple process. To improve the performance of bottom-emission organic light-emitting diodes (BEOLEDs), the effect of oxygen plasma treatment duration on the electrical properties of multi-metal Ni/Ag/Ni thin film anode was investigated. The results revealed that a Ni/Ag/Ni thin-film layer formed upon oxygen plasma treatment for 60s. Our indium-free bottom-emission OLEDs effectively increased the electrical and optical properties by improving their electron–hole recombination and doing a strong micro-cavity effect with the semitransparent multi-metal anode. The green bottom-emission OLEDs show a luminance of 14,280cd/m2, a luminous efficiency of 8.5cd/A, external quantum efficiency 2.6% EQE, a Commission Internationale de L’Eclairage coordinates of (0.32, 0.58) on flexible substrate.