Low temperature transient response and electroluminescence characteristics of OLEDs based on Alq 3

Yuan, Chao; Guan, Min; Zhang, Yang; Li, Yiyang; Liu, Shuangjie; Zeng, Yiping

doi:10.1016/j.apsusc.2017.04.041

Cited by 10 publications

(7 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The rise time and decay time of the two devices all show different characteristics after acceding to negative bias. When the switching voltage is changed from 0 to −7 V, DCZppy-based devices show a significantly decreased rise time and decay time with the increase of negative bias voltage . Because the direction of the electric field is opposite to the built-in electric field when the turn-off voltage is negative, it can accelerate the attenuation of the built-in electric field and help to release the trap charges.…”

Section: Resultsmentioning

confidence: 93%

“…When the switching voltage is changed from 0 to −7 V, DCZppy-based devices show a significantly decreased rise time and decay time with the increase of negative bias voltage. 37 Because the direction of the electric field is opposite to the built-in electric field when the turn-off voltage is negative, it can accelerate the attenuation of the built-in electric field and help to release the trap charges. With the change of negative bias voltage from 0 to −7 V, the trap release rate becomes faster and the decay time becomes shorter.…”

Section: Acs Applied Materials and Interfacesmentioning

confidence: 99%

See 1 more Smart Citation

High-Efficiency Blue Phosphorescent Organic Light-Emitting Devices with Low Efficiency Roll-Off at Ultrahigh Luminance by the Reduction of Triplet-Polaron Quenching

Zhang

Liu

et al. 2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

High-performance phosphorescent organic light-emitting devices (PhOLEDs) at high luminance are still a remaining problem that needs to be solved, especially blue PhOLEDs. Here, 5-(5-9H-carbazol-9-yl)pyridin-2-yl)-8-(9H-carbazol-9-yl)-5H-pyrido[3,2-b]indole (p2PCB2CZ) with excellent characteristics as a host is designed to realize a novel host–guest system without hole trapping effect in blue PhOLEDs. The device in which p2PCB2CZ and bis(3,5-difluoro-2-(2-pyridyl)phenyl-(2-carboxypyridyl)iridium(III) (FIrpic) is used as host and guest, respectively, is proposed to improve the performances of blue PhOLEDs at high luminance, especially at ultrahigh luminance (>30000 cd/m2). The maximum external quantum efficiency (EQE) of this type of blue PhOLEDs is 19.2%, while the maximum EQE of the reference blue PhOLEDs is 18.7%. Nevertheless, the p2PCB2CZ-based devices exhibit significant advantages at high luminance, because its EQE still attains to 10.8% even when the luminance increases to 30000 cd/m2, which is 1.67 times that of the reference device. From measurements based on steady-state and time-resolved spectroscopies, the reduction of triplet-polaron quenching in p2PCB2CZ-based devices is proved to be the main reason for improving the performances of blue PhOLEDs at high luminance.

show abstract

Section: Resultsmentioning

confidence: 93%

Section: Acs Applied Materials and Interfacesmentioning

confidence: 99%

High-Efficiency Blue Phosphorescent Organic Light-Emitting Devices with Low Efficiency Roll-Off at Ultrahigh Luminance by the Reduction of Triplet-Polaron Quenching

Zhang

Liu

et al. 2019

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

“…White organic light emitting device (WOLED) has great application potential in the field of full-color flat panel display and solid-state lighting due to its advantages of self-luminous, low power consumption, bright color and fast response [1]- [7]. In daily lighting applications, WOLED requires not only high efficiency How to cite this paper: Zhu, X.Y., Kou and color rendering index (CRI), but also high color and spectral stability [8] [9] [10].…”

Section: Introductionmentioning

confidence: 99%

The Study on the Relationship between Dynamic Balance Energy Distribution and Spectral Stability with Voltage Change in White Organic Light Emitting Diode

Zhu¹,

Kou²,

Li³

et al. 2023

OPJ

View full text Add to dashboard Cite

The stable spectrum can be obtained when the voltage changes, which is a necessary condition for the white organic light emitting diode (WOLED) device to be widely used in the field of solid-state lighting. However, with the increase of voltage, the movement of the recombination zone (RZ) is inevitable because the perfect bipolar host material is difficult to obtain, which will redistribute the energy in the light emitting layer (EML) and affect the stability of the spectrum. We fabricate a series of ternary hybrid WOLEDs with a simple structure by inserting ultra-thin PO-T2T into the blue exciplex (TCTA:TPBi) to form the green interface exciplex. Without considering the movement of RZ, device B2 realizes the dynamic balance energy distribution in EML and stable spectrum by controlling two processes of the Dexter energy transfer and exciton capture. By modifying the doping ratio of the host material, we also find that the broadened RZ is helpful to further improve the spectral stability of the device. When the voltage changes from 3 V to 7 V, the change range of color coordinates is only (0.026, 0.025).

show abstract

“…For example, Berleb et al [17] demonstrated low-temperature dependence of carrier transport in conducting polymers. Guan et al [18] reported the transient response of tris (8-hydroxyquinoline) aluminum-based OLEDs at low-temperature. Both examples constitute the current study of low temperature on the OLED performance.…”

Section: Introductionmentioning

confidence: 99%

Reliability of organic light-emitting diodes in low-temperature environment*

Pan¹,

Zhu²,

Liu³

et al. 2020

Chinese Phys. B

View full text Add to dashboard Cite

Organic light-emitting diode (OLED) is an electroluminescent technology that relies on charge-carrier dynamics and is a potential light source for variable environmental conditions. Here, by exploiting a self-developed low-temperature testing system, we investigated the characteristics of hole/electron transport, electro-optic conversion efficiency, and operation lifetime of OLEDs at low-temperature ranging from –40 °C to 0 °C and room temperature (25 °C). Compared to devices operating at room temperature, the carrier transport capability is significantly decreased with reducing temperature, and especially the mobility of the hole-transporting material (HTM) and electron-transporting material (ETM) at –40 °C decreases from 1.16 × 10−6 cm2/V⋅s and 2.60 × 10−4 cm2/V⋅s to 6.91 × 10−9 cm2/V⋅s and 1.44 × 10−5 cm2/V⋅s, respectively. Indeed, the temperature affects differently on the mobilities of HTM and ETM, which favors unbalanced charge-carrier transport and recombination in OLEDs, thereby leading to the maximum current efficiency decreased from 6.46 cd⋅A−1 at 25 °C to 2.74 cd⋅A−1 at –40 °C. In addition, blue fluorescent OLED at –20 °C has an above 56% lifetime improvement (time to 80% of the initial luminance) over the reference device at room temperature, which is attributed to efficiently dissipating heat generated inside the device by the low-temperature environment.

show abstract

Low temperature transient response and electroluminescence characteristics of OLEDs based on Alq 3

Cited by 10 publications

References 24 publications

High-Efficiency Blue Phosphorescent Organic Light-Emitting Devices with Low Efficiency Roll-Off at Ultrahigh Luminance by the Reduction of Triplet-Polaron Quenching

High-Efficiency Blue Phosphorescent Organic Light-Emitting Devices with Low Efficiency Roll-Off at Ultrahigh Luminance by the Reduction of Triplet-Polaron Quenching

The Study on the Relationship between Dynamic Balance Energy Distribution and Spectral Stability with Voltage Change in White Organic Light Emitting Diode

Reliability of organic light-emitting diodes in low-temperature environment*

Contact Info

Product

Resources

About