Session Index

S7. Display and Solid State Lighting

Display and Solid State Lighting II
Friday, Dec. 1, 2023  15:15-17:30
Presider: Prof. Tien-Lung Chiu (Yuan Ze University, Taiwan) Prof. Tzung-Fang Guo (National Cheng Kung University, Taiwan)
Room: 92277 (2F)
15:15 - 15:45
Manuscript ID.  0796
Paper No.  2023-FRI-S0702-I001
Invited Speaker:
Wai-yeung Wong
Recent Advances in Phosphorescent Metal Complexes
Wai-yeung Wong, The Hong Kong Polytechnic University (PolyU) (Hong Kong)

Organic light-emitting diodes (OLEDs) have received a great deal of interest owing to the huge market
application potentials as large-size, flexible, high-quality self-luminous display panels and lighting sources.
The performance of phosphorescent OLEDs is mainly limited by the phosphorescent transition metal
complexes (such as iridium(III), platinum(II)) and the hosts which can play a crucial role in furnishing
efficient energy transfer, balanced charge injection/transporting character and high quantum efficiency in
the devices. In this talk, the recent advances in the phosphorescent metal complexes functionalized with
various ligand moieties will be discussed from the point of view of their structure–property relationships.
Besides, near-infrared (NIR) light-emitting organic materials and their devices have aroused growing
interest recently due to their great potential for applications in photodynamic therapy, signal processing,
night-vision devices and information-secured displays. New and efficient strategies to develop NIR
phosphorescent emitters and soft salt complexes will also be presented and their optoelectronic applications
will be described.

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15:45 - 16:00 Award Candidate (Paper Competition)
Manuscript ID.  0725
Paper No.  2023-FRI-S0702-O001
Tzu-Yu Huang Modulating the Triplet-Triplet Annihilation to Singlet Fission Phenomena by Tuning the Thickness of Rubrene-Based Sub-bandgap Devices
Tzu-Yu Huang, Jun-Yu Cheng, Yulin Lin, Anas Mujahid, Tzung-Fang Guo, National Cheng Kung University (Taiwan)

Using magneto-electroluminescence (MEL), we report a significant change from triplet-triplet annihilation (TTA) to singlet fission (SF) in rubrene-based sub-bandgap devices through the modulation of rubrene thickness. We observe the dominant TTA when the rubrene layer is thinner, whereas; the thicker layer exhibits dominant SF during emission. In comparison to pristine rubrene devices, we find that the thickness of the rubrene layer in the sub-bandgap device effectively suppresses the TTA process.

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16:00 - 16:15 Award Candidate (Paper Competition)
Manuscript ID.  0268
Paper No.  2023-FRI-S0702-O002
Cheng-Rui Lu Emission Gate Driver Circuit with Adjustable Pulse for Use in AMOLED Displays
Cheng-Rui Lu, Cheng-Han Ke, National Cheng Kung University (Taiwan); Po-Cheng Lai, AUO Corporation (Taiwan); Chih-Lung Lin, National Cheng Kung University (Taiwan)

This work presents an emission (EM) gate driver circuit for AMOLED displays. The circuit decreases the gate voltage of the driving thin-film transistor (TFT) by capacitance coupling effect, enabling complete discharging. It also periodically stabilizes the output signal at a required low voltage (VGL). Furthermore, the EM signal can be adjusted depending on the input signals, meeting the requirements of AMOLED displays.

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16:15 - 16:30 Award Candidate (Paper Competition)
Manuscript ID.  0384
Paper No.  2023-FRI-S0702-O003
Yu-Hsuan Hsu Effects of ITO Contact Sizes on Performance of 40 μm and 10 μm Blue-Light MicroLEDs
Yu-Hsuan Hsu, Yi-Hsin Lin, Ray-Hua Horng, National Yang Ming Chiao Tung University (Taiwan)

In this study, the effect of contact ratio for blue light micro-light-emitting diode (μLED) with dimensions 40 μm and 10 μm were both assessed. As the contact ratio increased from 0.2 to 0.8, the turn-on voltage of μLEDs decreased and the leakage currents raised in both two dimensions devices. For optical properties, 40 μm μLED array with a 0.8 contact ratio presented the highest output power, which has the highest EQE value of 10.84%. However, the 0.5 contact ratio exhibited the highest EQE, 9.95%, in 10 μm μLED array. The simulation data using SpeCLED software agreed well with these experiments.

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16:30 - 16:45 Award Candidate (Paper Competition)
Manuscript ID.  0588
Paper No.  2023-FRI-S0702-O004
Chao-Che Wu Spiro-Acridine and Pyrimidine Bipolar Materials as TADF Host of TADF Emitters in an OLED
Chao-Che Wu, Han-Yun Szu, Chia-Hsun Chen, Man-Kit Leung, National Taiwan University (Taiwan); Tien-Lung Chiu, Yuan Ze University (Taiwan); Jiun-Haw Lee, National Taiwan University (Taiwan)

In this study, green thermally-activated delayed fluorescence (TADF) emitter was doped in a TADF host, consisting of the combination of acridine and pyrimidine units, and a spiro-ring structure, as the emitting layer (EML) of an organic light-emitting diode (OLED). By optimizing the doping concentration of the TADF emitter in the EML, maximum external quantum efficiency (EQEmax) of 11.73% was achieved, with Commission Internationale de l'Eclairage (CIE) coordinates at (0.321, 0.587). Notably, as the voltage was increased, the emission spectra displayed a distinct blue shift. Time-resolved electroluminescence (TrEL) measurements revealed prominent TADF characteristics, with a delayed emission time of 8 ms.

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16:45 - 17:00 Award Candidate (Paper Competition)
Manuscript ID.  0596
Paper No.  2023-FRI-S0702-O005
Bang-Wei Huang Optimizing Luminous Efficiency through Phosphor-in-Glass Thickness Reduction
Bang-Wei Huang, Yu-Yuan Chang, Hsing-Kun Shih, Chun-Nien Liu, Wood-Hi Cheng, National Chung Hsing University (Taiwan)

In this experiment, We use sodium glass powder (SiO2-Na2O3-Al2O3-Ca2O), mixed with yellow phosphor powder (Y3Al5O12:Ce3+), and sintered at 700°C to form a glass phosphor. Through uniformity measurement Ensure that the difference in color coordinates is less than 3.9×1-3 after the four-inch wafer is cut into phosphor crystals. Finally, the PiG-80μm was tested at 250°C for 1008 hours and measured with an integrating sphere. Lumen loss is 1.3%, still maintaining high reliability physical characteristics. Therefore, the PiG with reduced thickness and reduced porosity in this study has high industrial value and can be applied to automobile lights.

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17:00 - 17:15 Award Candidate (Paper Competition)
Manuscript ID.  0685
Paper No.  2023-FRI-S0702-O006
Zi-Jia Huang Colloidal Quantum Dot LEDs Package With Porous Microcarrier
Zi-Jia Huang, Ching Chang, National Taiwan University (Taiwan); Guan-Teng Lin, Chung-Ping Huang, National Yang Ming Chiao Tung University (Taiwan); Chien-Chung Lin, National Taiwan University (Taiwan)

The porous structured microcarrier powders were mixed with CQD/PDMS packages to improve the dispersion of QD particles. Results show QDs intensity and PLQY of the containing microcarriers perform the more uniform light filed and slower decline rate under high QD dose conditions.

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17:15 - 17:30 Award Candidate (Paper Competition)
Manuscript ID.  1049
Paper No.  2023-FRI-S0702-O007
Yu-Jui Chan Light Extraction Efficiency of Ultraviolet C AlGaN Light-Emitting Diodes
Yu-Jui Chan, Chia-Feng Lin, Chia-Lung Tsai, National Chung Hsing University (Taiwan)

Ultraviolet C AlGaN light-emitting diodes (UVC-LEDs) with an electrochemical (EC) treated hole array pattern were demonstrated. High electroluminescence (EL) emission images were observed in the UVC-LED with a hole array pattern. The EL emission peaks of the non-treated LED structure were measured at 277nm for AlGaN active layer and at 328 nm for the p-AlGN:Mg layer. By forming the EC-treated hole array pattern, the EL emission intensity of the treated LED was 1.8 times higher than that of the non-treated LED structure in the normal direction of the LED chips.

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