Realizing high efficiency/CRI/color stability in the hybrid white organic light emitting diode by manipulating exciton energy transfer

Wang, Lijun; Kou, Zhiqi; Wang, Baiqian; Zhou, Juan; Lu, Zhangyuchang; Li, Longxu

doi:10.1016/j.optmat.2021.111059

Cited by 10 publications

(4 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, the exciplex system with the TCTA/TPBI complex was already adopted as a blue emitter for constructing WOLEDs [ 15 ]. In addition, a tactic of adopting multiple Ir-complexes in multiple emission layers was also reported for forming WOLEDs [ 68 ].…”

Section: Resultsmentioning

confidence: 99%

“…For constructing high-efficiency organic light-emitting diodes (OLEDs), exciplex materials that combine hole transporting materials (HTMs) and electron transporting materials (ETMs) to form intermolecular charge transfer (CT) complexes have been widely investigated [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Because exciplexes tend to display undesirable red-shifted and broadened emissions, they were sometimes considered to negatively affect OLED performance.…”

Section: Introductionmentioning

confidence: 99%

“…However, one particular and apparent benefit of the broad spectrum was for the construction of white OLEDs (WOLEDs) with a high color rendering index. Therefore, exciplexes were found to be of utility as emitters in WOLEDs [ 12 , 13 , 14 , 15 , 16 ]. Besides being used as emitting materials, exciplexes can also be adopted as cohosts in the emissive layer (EML).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Mechanism of Ir(ppy)3 Guest Exciton Formation with the Exciplex-Forming TCTA:TPBI Cohost within a Phosphorescent Organic Light-Emitting Diode Environment

Park

Cho

Rhee

2022

IJMS

View full text Add to dashboard Cite

Cohosts based on hole transporting and electron transporting materials often act as exciplexes in the form of intermolecular charge transfer complexes. Indeed, exciplex-forming cohosts have been widely developed as the host materials for efficient phosphorescent organic light-emitting diodes (OLEDs). In host–guest systems of OLEDs, the guest can be excited by two competing mechanisms, namely, excitation energy transfer (EET) and charge transfer (CT). Experimentally, it has been reported that the EET mechanism is dominant and the excitons are primarily formed in the host first and then transferred to the guest in phosphorescent OLEDs based on exciplex-forming cohosts. With this, exciplex-forming cohosts are widely employed for avoiding the formation of trapped charge carriers in the phosphorescent guest. However, theoretical studies are still lacking toward elucidating the relative importance between EET and CT processes in exciting the guest molecules in such systems. Here, we obtain the kinetics of guest excitation processes in a few trimer model systems consisting of an exciplex-forming cohost pair and a phosphorescent guest. We adopt the Förster resonance energy transfer (FRET) rate constants for the electronic transitions between excited states toward solving kinetic master equations. The input parameters for calculating the FRET rate constants are obtained from density functional theory (DFT) and time-dependent DFT. The results show that while the EET mechanism is important, the CT mechanism may still play a significant role in guest excitations. In fact, the relative importance of CT over EET depends strongly on the location of the guest molecule relative to the cohost pair. This is understandable as both the coupling for EET and the interaction energy for CT are strongly influenced by the geometric constraints. Understanding the energy transfer pathways from the exciplex state of cohost to the emissive state of guest may provide insights for improving exciplex-forming materials adopted in OLEDs.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanism of Ir(ppy)3 Guest Exciton Formation with the Exciplex-Forming TCTA:TPBI Cohost within a Phosphorescent Organic Light-Emitting Diode Environment

Park

Cho

Rhee

2022

IJMS

View full text Add to dashboard Cite

show abstract

“…In recent years, the organic light-emitting diode (OLED) has attracted many attentions of researchers and made significant progress due to its excellent performance, such as high luminance, light weight, bright colors [1] [2] [3]. On the one hand, OLED with stable spectrum can prevent the color distortion of the display device and greatly enhance the user's visual experience in the field of flat panel display [4] [5] [6] [7] [8]. On the other hand, the color-tunable OLED (CT-OLED) with unstable spectrum has also important application in the field of lighting industry.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Energy Transfer on the Color Temperature Change in Color-Tunable Organic Light Emitting Diodes with Interface Exciplex

Li¹,

Kou²,

Zhu³

et al. 2023

OPJ

Self Cite

View full text Add to dashboard Cite

The color-tunable white organic light-emitting diode (CT-WOLED) with wide correlation color temperature (CCT) has many advantages in optimizing the artificial light source to adapt to the human physiological cycle. The research on the change trend of CCT and the law of extending the change range of CCT will help to further improve the performance of this kind of device. The present work fabricated a series of CT-WOLED devices with a simple structure, which are all composed of two ultra-thin phosphor layers (PO-01 and Flrpic) and a spacer interlayer. The yellow interface exciplex (TCTA/PO-T2T) formed between the spacer layer (PO-T2T) and transmission material (TCTA) in EML will decrease the CCT value at low voltage. The relationship between the energy transfer in EML and CCT change trend is investigated by adjusting the interface exciplexes and the thickness of the interlayer or the phosphor layer in devices A, B and C, respectively. The results demonstrate that a simple OLED device with an interlayer inserted between two ultra-thin phosphor layers can achieve a wider CCT span from 3359 K to 6451 K at voltage increases from 2.75 V to 8.25 V.

show abstract

Stable yellow light emission from lead-free copper halides single crystals for visible light communication

Wang

Tang

Yang

et al. 2023

Nano Materials Science

View full text Add to dashboard Cite

Realizing high efficiency/CRI/color stability in the hybrid white organic light emitting diode by manipulating exciton energy transfer

Cited by 10 publications

References 32 publications

Mechanism of Ir(ppy)3 Guest Exciton Formation with the Exciplex-Forming TCTA:TPBI Cohost within a Phosphorescent Organic Light-Emitting Diode Environment

Mechanism of Ir(ppy)3 Guest Exciton Formation with the Exciplex-Forming TCTA:TPBI Cohost within a Phosphorescent Organic Light-Emitting Diode Environment

The Influence of Energy Transfer on the Color Temperature Change in Color-Tunable Organic Light Emitting Diodes with Interface Exciplex

Stable yellow light emission from lead-free copper halides single crystals for visible light communication

Contact Info

Product

Resources

About