Vadim Adamovich

Realizing white phosphorescent 100 lm/W OLED efficacy

OLED display manufacturers are interested in white organic light emitting devices (WOLEDTMs) because these devices, together with color filters, eliminate the need for high resolution shadow masks. Additionally, WOLEDs are well suited for general-purpose illumination, since their power efficacies are approaching fluorescent lamps. A new structure was developed that had the following characteristics that were measured using a spot meter: at 100 cd/m2 normal luminance, EQE = 20%, power efficacy is 34 lm/W, operating voltage = 3.6 V, CIE = (0.44, 0.44) and CRI = 75.

White phosphorescent organic light emitting devices

OLED display manufacturers are interested in white organic light emitting devices (WOLEDs) because these devices, together with color filters, eliminate the need for high resolution shadow masks, and are scalable beyond Gen 4 substrates. Additionally, WOLEDs are well suited for general-purpose illumination, since their power efficacies are approaching fluorescent lamps. A new structure was developed that had the following characteristics that were measured using a 20“ integrating sphere: at 100 cd/m normal luminance, EQE = 35%, power efficacy is 62 lm/W, operating voltage = 4.4 V, CIE = (0.33, 0.43) and CRI = 70.

OLED Device Operational Lifetime: Insights and Challenges

This paper discusses some of the most important intrinsic and extrinsic factors that affect the organic light-emitting devices (OLEDs) stability. OLEDs lifetime can be greatly improved through materials design by improving the redox properties, thermal properties, and charge transporting properties. Extrinsic factors, such as materials purity, are also discussed.

52.4: Highly Efficient Phosphorescent OLED Lighting Panels for Solid State Lighting

We present a 15 cm × 15 cm PHOLEDTM lighting panel that operates with 50 lm/W efficacy, CRI = 87, CCT = 3055 K and lifetime to LT70 ≅ 10,000 hrs at 1,000 cd/m2. We also present a panel with 58 lm/W efficacy, CRI = 86 and CCT = 2790 K at 1,000 cd/m2, and a small-area lighting pixel with 109 lm/W efficacy, CRI = 80, CCT = 3295 K and lifetime to LT70 ≅ 15,000 hrs at 1,000 cd/m2. A highly stable light blue phosphorescent host-emitter system is used to reduce power consumption, extend operational lifetime and demonstrate exceptional emission color stability with aging.

Recent progress in high-efficiency phosphorescent OLED technology

A key performance attribute for widespread commercialization of OLED technology is achieving maximum power efficiency along with color chromaticity and operational lifetime. Towards this goal, phosphorescent-OLED (PHOLED) devices have demonstrated potential. Recent PHOLED device results show both excellent device efficiencies and long lifetimes towards the commercialization of low power consumption, full color, passive- and active-matrix (both polysilicon and amorphous-silicon backplane technologies) OLED displays.

High-performance phosphorescent white-stacked organic light-emitting devices for solid-state lighting

In this work we report exceptional efficacy, lifetime and color stability for all-phosphorescent white stacked organic light-emitting devices (SOLED®s). We report data for all-phosphorescent white SOLED pixels with two emissive units connected in series by a charge generation layer (CGL). At 3,000  cd/m 2 , efficacy = 54 to 56  lm/W and lifetime to 70% of initial luminance LT70 ≈ 20,000  h, with color rendering index (CRI) = 82 to 83 and chromaticity meeting Energy Star criteria. We further report data for a 15  cm×15  cm white SOLED panel that operates at 3,000  cd/m 2 with 48  lm/W efficacy, CRI = 86 and chromaticity meeting Energy Star criteria. The panel has extremely low operating temperature that is only 6.4°C above ambient, and exceptional lifetime of LT70 ≈ 13,000  h when operated at 3,000  cd/m 2 .

Impact of Trapped Charge and Interface Defects on the Degradation of the Optical and Electrical Characteristics in

Electroluminescence degradation mechanisms in small-molecule-based organic light-emitting diodes (OLEDs) have been investigated. We focused on intrinsic degradation phenomena that determine the decrease in the optical power of OLEDs during standard operation. The study was carried out on simplified OLED structures, by means of combined optical and electrical characterization techniques. The results of this analysis provide information on the physical processes responsible for OLED degradation, suggesting a strong correlation between the reduction in the luminance intensity of the devices and the creation of both positive trapped charge and neutral electron traps at the Alq3/NPD interface. The evidence reported in this paper supports the hypothesis that degradation is due to the instability of the cationic Alq3 species.

\hbox{NPD/Alq}_{3}

We present a novel all-phosphorescent AMOLED pixel architecture with a red, green, light blue and deep blue sub-pixel design. The highly efficient light blue reduces power consumption by 33% compared to an equivalent conventional RGB display using a fluorescent blue sub-pixel. Furthermore, by using a light and deep blue sub-pixel layout, the lifetime of the display will be significantly increased due to the reduced on-time required for the deep blue sub-pixel. Here we demonstrate this new design in a 2.5-inch AMOLED panel.

OLEDs

Phosphorescent organic light emitting device (PHOLEDTM) technology has demonstrated record high efficiencies and long operational stability. Here we report on the introduction of an additional charge transporting dopant into the device emissive layer to further improve the luminous efficiency and device lifetime. The performance enhancement is attributed to the separation of polarons and excitons in the device emissive layer, which results in reduced triplet-triplet and triplet-polaron interactions as well as minimizing self quenching and reabsorption. Specifically we report a 50% improvement in the luminous efficiency of a red PHOLED and a 3 fold improvement of the device lifetime due to the use of dual doping. A dual doped sRGB red device with 28 cd/A and the lifetime over 300,000h at 1,000 nits is demonstrated.

43.3: Power Efficient AMOLED Display with Novel Four Sub-Pixel Architecture and Driving Scheme

As organic light emitting device (OLED) technology is building up momentum in the commercial marketplace, phosphorescent OLEDs (PHOLEDsTM) are proving themselves to be an ideal display medium for a wide range of product applications: from small mobile displays to large area TVs. As part of this work we continue to advance PHOLED technology by new materials design and device architectures. For example a green PHOLED with 4.3 V, 70 cd/A, 50 lm/W and > 10,000 hours lifetime at 1,000 cd/m2 is reported. PHOLEDs enable very low power consumption displays with low display operating temperatures, and can be deposited by a range of different deposition techniques. Along with state-of-the-art device performance we report results on the ruggedness of PHOLED materials in high volume manufacturing environments.