Conference presentations and Papers


We not only apply for patents on the findings and results of our research and development, but also actively present them at academic conferences and submit them for publication. Here we introduce some of the conference presentations and papers that have attracted attention.


Published in Communications Materials

SEL papers were published in the open-access journal Communications Materials by Springer Nature, the world's largest publisher of influential journals such as Nature.


Paper related to single-crystalline indium oxide FET suitable for 3D stacking

S. Yamazaki et al., High-performance single crystalline In2O3 field effect transistor toward three-dimensional very-large-scale integration circuits. Commun. Mater., 2024; 5(184): 1-11. https://doi.org/10.1038/s43246-024-00625-x

This paper reports on a vertical field-effect transistors (VFETs) using indium oxide. With the use of CAAC-IGZO as a seed, we have succeeded in fabricating VFETs using indium oxide having no grain boundaries in a channel formation region. The VFETs do not require a single-crystal substrate such as YSZ and have a shape that facilitates integration, which enables application to VLSI. Since the VFETs using indium oxide have an extremely low off-state current compared with Si transistors, it is expected to help servers save power and then prevent global warming.




Paper related to LiCoO2 which changes into the O3’ phase in charging

M. Mikami et al., Controlling lithium cobalt oxide phase transition using molten fluoride salt for improved lithium-ion batteries. Commun. Mater., 2024; 5(108): 1-11.
https://doi.org/10.1038/s43246-024-00543-y

This paper reports on improvement of lithium cobalt oxide (LiCoO2) which is widely used for batteries in smartphones and so on. By heating a mixture of lithium cobalt oxide, magnesium, and fluoride, Mg coating and doping is effectively conducted; thus, deterioration of lithium cobalt oxide in charging and discharging successfully prevented. It is proved that the crystal structure of the modified lithium cobalt oxide in charging changes to a phase transition to novel O3’ phase without undergoing a transformation to the H1-3 phase which is conventionally known.






WILEY Top Downloaded Article

Several SEL papers published in the Journal of the Society of Information Display (JSID) and the International Journal of Ceramic Engineering and Science (IJCES) were selected as top downloads. The rankings are made by John Wiley & Sons, the world's leading academic publisher.


Ranked in the top 10% of the most downloaded papers published in JSID from January to December 2022.

K. Kato et al., 5,291-ppi OLED display enabled by monolithic integration of C-axis-aligned crystalline IGZO FET and Si CMOS. J. Soc. Inf. Display, 2022; 30(9): 690-698. https://doi.org/10.1002/jsid.1167


This paper reports on an OLED display (pixel density: 5,291ppi) for AR/VR applications. For the first time in the world, we have fabricated an OLED display with monolithic integration of Si CMOS and oxide semiconductor FETs (OSFETs).


Our paper selected as WILEY Top Downloaded Article



Ranked in the top 10% of the most downloaded articles published in IJCES in 2018-2019.

S. Yamazaki et al., Crystalline IGZO ceramics (crystalline oxide semiconductor)-based devices for artificial intelligence. Int. J. Ceramic Eng. Sci., 2019; 1: 6-20. https://doi.org/10.1002/ces2.10005


This paper reports on an oxide semiconductor with a c-axis aligned crystalline structure as a next-generation LSI material to be a potential replacement for Si. The properties of FETs based on this crystalline oxide semiconductor enable low-power memory devices (DOSRAM and NOSRAM), which are expected to be applied to AI products requiring low power consumption in the future.



Ranked in the top 10% of the most downloaded articles published in JSID in 2018-2019.

T. Kamada et al., OLED display incorporating organic photodiodes for fingerprint imaging. J. Soc. Inf. Display, 2019; 27: 361-371. https://doi.org/10.1002/jsid.786


This paper reports on a display that incorporates an organic image sensor in each pixel of the entire display surface. Fingerprint imaging is possible anywhere on the entire display screen without an external module for fingerprint imaging. Touch sensing and scanning functions are also possible, and applications in healthcare devices and various flexible devices are expected.



S. Katsui et al., A 5291-ppi organic light-emitting diode display using field-effect transistors including a c-axis aligned crystalline oxide semiconductor. J. Soc. Inf. Display, 2019; 27: 497-506. https://doi.org/10.1002/jsid.822


This paper reports on a high-resolution OLED display that uses CAAC-OS FETs as the backplane and exceeds the 5000 ppi required for virtual reality (VR) displays. The CAAC-OS FETs can be miniaturized, and the ability to control the current required for the small pixels in the display has been verified.



Y. Takita et al., Highly efficient deep-blue fluorescent dopant for achieving low-power OLED display satisfying BT.2020 chromaticity. J. Soc. Info. Display, 2018, 26: 55-63. https://doi.org/10.1002/jsid.634


In this paper, we report on a new blue fluorescent dopant with a heteroaromatic ring skeleton instead of the conventional pyrene skeleton. OLEDs with this new dopant achieved deeper blue chromaticity and higher external quantum efficiency. It was also found that OLED panels with this new dopant consume significantly less power (24% less than conventional panels).



Selected as one of the 20 most downloaded JSID articles published in 2016-2017 in the first 12 months after publication.

T. Takahashi et al., Emission mechanism in phosphorescent and fluorescent OLED utilizing energy transfer from exciplex to emitter. J. Soc. Info. Display, 2016, 24: 360-370. https://doi.org/10.1002/jsid.454

This paper discusses the process and effectiveness of energy transfer in “Exciplex to Triplet Energy Transfer (ExTET)” and reports on recent advances in ExTET technology. This energy transfer can improve efficiency, lower drive voltage, and extend lifetime. We have also found that such energy transfer is also effective in fluorescent OLEDs as “exciplex-enhanced fluorescence (ExEF)” to increase quantum efficiency.


▲Fig. 8 Concept of exciplex-enhanced fluorescence



Selected as one of the 15 most downloaded articles published by WILEY in 2014 (in the field of electronics and communication engineering).

S. Yamazaki et al., Back-channel-etched thin-film transistor using c-axis-aligned crystal In-Ga-Zn oxide, J. Soc. Info. Display, 2014, 22(1), 55. https://doi.org/10.1002/jsid.211

This paper reports on a back-channel-etched TFT using c-axis-aligned crystal In-Ga-Zn oxide thin film. Back-channel-etched IGZO TFTs have been difficult to obtain stable TFT characteristics with a short channel length because of a large damage to the IGZO thin film in the manufacturing process. However, by using CAAC-IGZO thin film with crystallinity, it was possible to obtain stable TFT characteristics with little variation even when the channel length is short.



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