• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.810-813
• /
• 2009

Fluorene derivatives are well-known in the polymer OLEDs due to their good charge carrying property. In this work, we synthesized a series of conjugated copolymers based fluorene derivative and phenylamine units by using Buchwald-Hartwig reaction in order to investigate their photoreactivities and use as the HIL/HTL layers of OLEDs using solution processes.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.229-230
• /
• 2000

The current status of OLEDs technology is reviewed. Comparison has been made between small molecule based OLEDs and polymer LEDs. In addition, advantages of OLEDs technology and technical issues for commercialization are addressed. Details of these issues will be discussed at the meeting.

• Transactions on Electrical and Electronic Materials
• /
• v.16 no.3
• /
• pp.124-129
• /
• 2015

Organic electronics are the domain in which the components and circuits are made of organic materials. This new electronics help to realize electronic and optoelectronic devices on flexible substrates. In recent years, organic materials have replaced conventional semiconductors in many electronic components such as, organic light-emitting diodes (OLEDs), organic field-effect transistors (OFETs) and organic photovoltaic (OPVs). It is well known that organic light emitting diodes (OLEDs) have many advantages in comparison with inorganic light-emitting diodes LEDs. These advantages include the low price of manufacturing, large area of electroluminescent display, uniform emission and lower the requirement for power. The aim of this paper is to model polymer LEDs and OLEDs made with small molecules for studying the electrical and optical characteristics. The purpose of this modeling process is, to obtain information about the running of OLEDs, as well as, the injection and charge transport mechanisms. The first simulation structure used in this paper is a mono layer device; typically consisting of the poly (2-methoxy-5(2'-ethyl) hexoxy-phenylenevinylene) (MEH-PPV) polymer sandwiched between an anode with a high work function, usually an indium tin oxide (ITO) substrate, and a cathode with a relatively low work function, such as Al. Electrons will then be injected from the cathode and recombine with electron holes injected from the anode, emitting light. In the second structure, we replaced MEH-PPV by tris (8-hydroxyquinolinato) aluminum (Alq₃). This simulation uses, the Poole-Frenkel -like mobility model and the Langevin bimolecular recombination model as the transport and recombination mechanism. These models are enabled in ATLAS- SILVACO. To optimize OLED performance, we propose to change some parameters in this device, such as doping concentration, thickness and electrode materials.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2008.10a
• /
• pp.521-522
• /
• 2008

An etch-less simple method was developed to fabricate two-dimensional nanostructures on glass substrate directly by using UV curable polymer resin and UV nanoimprint lithography in order to improve output coupling efficiency of OLEDs. OLEDs integrated on nanoimprinted substrates enhanced electro-luminance intensity by up to 50% compared with the conventional device.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08a
• /
• pp.694-697
• /
• 2007

We demonstrate the use of screen printing in the fabrication of highly efficient phosphorescent polymer organic-light-emitting devices (OLEDs) based on a green-emitting $Ir(ppy)_3$ and a host polymer PVK. We incorporate PBD in the polymer host as an electron-transporting dopant and ${\alpha}-NPD$ as a hole transporting dopant. The best screen printed single-layer device exhibits very high peak luminous efficiency of 63 cd/A at a relatively high operating voltage of 17.1 V at the luminance of $650\;cd/m^2$. We observed the highest luminance of $21,000\;Cd/m^2$ at 35V. Due to the high operating voltage, despite of the high peak luminous efficiency the peak power efficiency was found to be 12.2 lm/W at the luminance of $470\;cd/m^2$ (15.9 V).

• Bulletin of the Korean Chemical Society
• /
• v.32 no.11
• /
• pp.4075-4078
• /
• 2011

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1813-1818
• /
• 2006

We demonstrate a new approach to form gradient hole injection layer (HIL) in organic light-emitting diodes (OLEDs). Single spincoating of hole-injecting conducting polymer compositions with a perfluorinated ionomer results in gradient workfunction through the layer by self-organization, which lead to remarkably efficient single layer polymer light-emitting diodes (PLEDs) (${\sim}21$ cd/A). The device lifetime was significantly improved (${\sim50$ times) compared with the conventional hole injection layer, poly(3,4-ethylenedioxy-thiophene)/polystyrene sulfonate. This solution processed HIL also produced dramatically enhanced luminous efficiency (${\sim}34$ cd/A) in vacuum- deposited green fluorescent OLEDs while the vacuum deposited HIL gave the luminous efficiency of ${\sim}23$ cd/A in the same device structure.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2003.07a
• /
• pp.966-969
• /
• 2003

Thin film capacitors with Al-Polymer-Al sandwich structure were fabricated. The bottom and top aluminium (Al) electrodes were deposited by vacuum evaporation and copper phthalocyanine (CuPc), polyaniline-emeraldine base (Pani-EB) and cobalt phthalocyanine/polyaniline - emeraldine base (CoPc /Pani-EB) blend films (which can be used as buffer hole injection layer in OLEDs) were deposited by spin coating technique. X-ray diffractograms indicated amorphous nature of the polymer films whose thicknesses were measured by capacitance and Rutherford Backscattering Spectrometry (RBS) methods. AC conduction studies revealed that the conduction mechanism responsible in these films is variable range hopping of polarons. From D.C conduction studies, it is observed that, the nature of conduction is ohmic in the lower fields and at higher fields the dominating D.C conduction is of Poole-Frenkel type.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.337-342
• /
• 2004

Since 1992, Philips has been developing polymer OLEDs resulting in a first commercial monochrome display just 10 years later. Philips is now focusing on the technology development required to mass-produce full-color polymer OLDE displays, based on passive and active-matrix addressing. High precision inkjet printing has been chosen as the deposition technology for the OLED material. In this paper, we give an overview of the activities of Philips in the area of mobile OLED applications and explore the route towards large screen OLED television.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2004.08a
• /
• pp.623-624
• /
• 2004

The coating and estimation of gas and moisture barriers on polymer and glass substrates are receiving very much attention in passivation of organic light emitting devices (OLEDs). In this study, the encapsulation and lifetime measurement techniques of OLEDs were presented. The degradation mechanisms of bare and encapsulated OLEDs were investigated by the visual lifetime measurement (VLM) system with the parameters such as a pixel luminance(L), a luminance rms roughness(dL), a brightness area ratio(R), an edge degradation depth(D), etc.