Improved stability of organic light-emitting diode with aluminum cathodes prepared by ion beam assisted deposition

Abstract

We have fabricated highly stable organic electroluminescent devices based on spin-coated poly-p-phenylene-vynylene (PPV) thin films. The electrical properties of aluminum cathode, prepared by ion beam assisted deposition, on PPV have been investigated and compared to those by thermal evaporation. Although energetic particles of Al assisted by Ar C ion may damage the organic material, I-V-L characteristics are improved by applying thin Al buffer layer. In addition, a dense Al cathode inhibits the permeation of H 2 O and O 2 into PPV film through pinhole defects, and thus retards dark spot growth. It may be deduced from highly packed structure of Al cathode with an increase in the contact area between Al and PPV that reduce the contact resistance. In conclusion, the lifetime of organic light-emitting device (OLED) has been extended effectively by dense Al film through ion beam assisted deposition process. q

Disruptive characteristics and lifetime issues of OLEDs

“…An ion-beam-assisted aluminum layer deposition has extensively enhanced the lifetime of OLED devices. 118 Due to the poor barrier performance of polymer substrates, a thin encapsulation technique is required on both sides of the device to prevent atmospheric moisture and oxygen penetration. 119 Recently, a multilayer of atomic layer deposition (ALD)/molecular layer deposition (MLD) combination has been proposed by Dameron et al 120 They reported that the effective water vapor transmission rates are also reduced for the Al 2 O 3 /SiO 2 ALD bilayer.…”

Quantum Dot-Based Light Emitting Diodes (QDLEDs): New Progress

“…In recent years, a lot of researches are conducted to achieve efficient and low-energy light sources. Inorganic light emitting diode (LED) and organic light emitting diode (OLED) have been introduced as a result of these efforts to achieve solid-state light sources [1][2][3][4][5][6]. The outdoor application is one of the important markets for LED lighting.…”

Electroless Silver Plating of the Surface of Organic Semiconductors

“…So far, some soft-metallization techniques successfully applied to organic semiconductors have been described. They rely basically on three approaches: lamination, , ion beam assisted deposition, and inkjet printing. − The common prerogative of the three approaches is to reduce the process temperature in order to not alter the semiconductor surface. Electroless plating methods are already reliable metallization methods of organic materials.…”