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External compensation for high-resolution active matrix organic light-emitting diode displays

Verschueren, L. (author), Ameys M., (author), Velazquez Lopez M., (author), Roose F. de, (author), Bonnifait M., (author), Smout S., (author), Ke T.H., (author), Vandenplas E., (author), Kronemeijer A.J., (author), Steudel S., (author), Genoe J., (author), Dehaene W., (author), Myny K., (author)

Two different external compensation methods for high-resolution active matrix organic light-emitting diode (AMOLED) displays are presented and compared. Both compensation methods are implemented using a small pixel circuit, namely, a 3T2C and a 2T1C pixel circuit, allowing high-resolution displays. Due to the simple driving schemes, these...

article 2021

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A 2t1c amoled display with external compensation reducing on-panel current variations to 0.079%

Verschueren, L. (author), Ameys, M. (author), Lopez, M.V. (author), Smout, S. (author), Ke, T.H. (author), Vandenplas, E. (author), Kronemeijer, A.J. (author), Heremans, P. (author), Genoe, J. (author), Dehaene, W. (author), Myny, K. (author)

This paper presents a new compensation principle using a 2T1C pixel circuit. The implementation shows significant improvement in uniformity for all grey-levels, due to compensation for both VT and β-factor variations. The resulting current variation after compensation in the characterized display area reaches values down to 0.079%.

conference paper 2020

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Igzo-based identification tags communicating with everyday touchscreens

Papadopoulos, N. (author), Celiker, H. (author), Qiu, W. (author), Ameys, M. (author), Smout, S. (author), Willegems, M. (author), Deroo, F. (author), Steen, J.-L. (author), Kronemeijer, A.J. (author), Dehouwer, M. (author), Mityashin, A. (author), Gehlhaar, R. (author), Dehaene, W. (author), Myny, K. (author)

In this work, we demonstrate a capacitive coupled data transfer with flexible thin-film electronics using touchscreen as ubiquitous reader interface. The capacitive communication to the touchscreen is proven using a 64-bit metal-oxide thin-film capacitive-coupled identification tag. The tag is powered by a thin film battery or thin-film...

conference paper 2020

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Touchscreen tags based on thin-film electronics for the Internet of Everything

Papadopoulos, N. (author), Qiu, W. (author), Ameys, M. (author), Smout, S. (author), Willegems, M. (author), Deroo, F. (author), van der Steen, J.L. (author), Kronemeijer, A.J. (author), Dehouwer, M. (author), Mityashin, A. (author), Gehlhaar, R. (author), Myny, K. (author)

Capacitive touchscreens are increasingly widespread, featuring in mobile phones and tablets, as well as everyday objects such as cars and home appliances. As a result, the interfaces are uniquely placed to provide a means of communication in the era of the Internet of Everything. Here, we show that commercial touchscreens can be used as reader...

article 2019

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Metal-oxide readout electronics based on Indium-Gallium-Zinc-Oxide and Indium-Tin-Zinc-Oxide for in-panel fingerprint detection application

Papadopoulos, N. (author), Steudel, S. (author), Smout, S. (author), Willegems, M. (author), Nag, M. (author), Ameys, M. (author), Kronemeijer, A.J. (author), Heremans, P. (author), Myny, K. (author)

This work describes integrated readout electronics for on-panel fingerprint detection, focusing on two key building blocks: charge sense amplifier (CSA) and analog-to-digital converter (ADC). The CSA has been realized in a dual-gate self-aligned IGZO thin-film transistor (TFT) technology with channel length downsizing to 3µm, enabling 1.3mm...

conference paper 2019

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5-3: Distinguished Paper: Power Saving through State Retention in IGZO-TFT AMOLED Displays for Wearable Applications

Steudel, S. (author), van der Steen, J.L. (author), Nag, M. (author), Ke, T.H. (author), Smout, S. (author), Bel, T. (author), van Diesen, K. (author), de Haas, G. (author), Maas, J. (author), de Riet, J. (author), Rovers, M. (author), Verbeek, R. (author), Huang, Y.Y. (author), Chiang, S.C. (author), Ameys, M. (author), de Roose, F. (author), Dehaene, W. (author), Genoe, J. (author), Heremans, P. (author), Gelinck, G. (author), Kronemeijer, A.J. (author)

We present a qHD (960x540 with 3 sub-pixels) top-emitting AMOLED display with 340ppi resolution using a self-aligned (SA) IGZO TFT backplane on polyimide-foil with humidity barrier. The back plane process flow is based on a 7 layer photolithography process with a CD=4um. We implement a 2T1C pixel engine and use commercial source driver IC made...

conference paper 2017

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Impact of source/drain contacts formation of self-aligned amorphous-IGZO TFTs on their negative-bias-illumination-stress stabilities

Nag, M. (author), Steudel, S. (author), Smout, S. (author), Bhoolokam, A. (author), Genoe, J. (author), Cobb, B. (author), Kumar, A. (author), Groeseneken, G. (author), Heremans, P. (author)

In this study, we have compared the performance of self-aligned a-IGZO thin-film transistors (TFTs) whereby the source/drain (S/D) region's conductivity enhanced in three different ways, that is, using SiNx interlayer plasma (hydrogen diffusion), using calcium (Ca as reducing metal) and using argon plasma (changing the atomic ratio). All these...

article 2015

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Paper S12 5 : Self-aligned a-IGZO TFTs : Impact of S/D contacts formation on their Negative-Bias-Illumination-Stress (NBIS) instability

Nag, M. (author), Steudel, S. (author), Smout, S. (author), Bhoolokam, A. (author), Genoe, J. (author), Cobb, B. (author), Kumar, A. (author), Groeseneken, G. (author), Heremans, P. (author)

In this work, we present the impact of S/D contact formation, that is, by SiN plasma doping (hydrogen incorporation), metallic reduction (by calcium) and by argon plasma (compositional change) on NBIS instabilities of self-aligned a-IGZO TFTs.

article 2015

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Circuits and AMOLED display with self-aligned a-IGZO TFTs on polyimide foil

Nag, M. (author), Bhoolokam, A. (author), Smout, S. (author), Willegems, M. (author), Muller, R. (author), Myny, K. (author), Schols, S. (author), Ameys, M. (author), Genoe, J. (author), Ke, T.H. (author), Vicca, P. (author), Ellis, T. (author), Cobb, B. (author), Kumar, A. (author), van der Steen, J.L.P.J. (author), Gelinck, G. (author), Fukui, Y. (author), Obata, K. (author), Groeseneken, G. (author), Heremans, P. (author), Steudel, S. (author)

A process to make self-aligned top-gate amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) on polyimide foil is presented. The source/drain (S/D) region's parasitic resistance reduced during the SiN interlayer deposition step. The sheet resistivity of S/D region after exposure to SiN interlayer deposition decreased to 1.5...

article 2015

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Flexible AMOLED display with integrated gate driver operating at operation speed compatible with 4k2k

Steudel, S. (author), Cobb, B. (author), Nag, M. (author), Obata, K. (author), Murata, K.M. (author), Schols, S. (author), Vicca, P. (author), Ke, T.H. (author), Smout, S. (author), Willegems, M. (author), Ameys, M. (author), Bhoolakam, A. (author), Kumar, A. (author), Kumar, A. (author), van der Steen, J.L. (author), Genoe, J. (author), Gelinck, G.H. (author), Heremans, P.L. (author)

We present a QVGA (320x240 with 3 sub-pixel) top-emitting AMOLED display with 250ppi resolution using a self-aligned (SA) IGZO TFT backplane on polyimide-foil with full barrier. The back plane process flow is based on a 7 layer photolithography process. The aperture ratio of the top-emitting OLEDs is approx. 80%. An integrated gate driver is...

article 2015

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Low-temperature formation of source–drain contacts in self-aligned amorphous oxide thin-film transistors

Nag, M. (author), Muller, R. (author), Steudel, S. (author), Smout, S. (author), Bhoolokam, A. (author), Myny, K. (author), Schols, S. (author), Genoe, J. (author), Cobb, B. (author), Kumar, A. (author), Gelinck, G. (author), Fukui, Y. (author), Groeseneken, G. (author), Heremans, P. (author)

We demonstrated self-aligned amorphous-Indium-Gallium-Zinc-Oxide (a-IGZO) thin-film transistors (TFTs) where the source–drain (S/D) regions were made conductive via chemical reduction of the a-IGZO via metallic calcium (Ca). Due to the higher chemical reactivity of Ca, the process can be operated at lower temperatures. The Ca process has the...

article 2015

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A thin-film microprocessor with inkjet print-programmable memory

Myny, K. (author), Smout, S. (author), Rockelé, M. (author), Bhoolokam, A. (author), Ke, T.H. (author), Steudel, S. (author), Cobb, B. (author), Gulati, A. (author), Rodriguez, F.G. (author), Obata, K. (author), Marinkovic, M. (author), Pham, D.V. (author), Hoppe, A. (author), Gelinck, G.H. (author), Genoe, J. (author), Dehaene, W. (author), Heremans, P. (author)

The Internet of Things is driving extensive efforts to develop intelligent everyday objects. This requires seamless integration of relatively simple electronics, for example through ‘stick-on’ electronics labels. We believe the future evolution of this technology will be governed by Wright’s Law, which was first proposed in 1936 and states that...

article 2014

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Novel back-channel-etch process flow based a-IGZO TFTs for circuit and display applications on PEN foil

Nag, M. (author), Rockele, M. (author), Steudel, S. (author), Chasin, A. (author), Myny, K. (author), Bhoolokam, A. (author), Willegems, M. (author), Smout, S. (author), Vicca, P. (author), Ameys, M. (author), Ke, T.H. (author), Schols, S. (author), Genoe, J. (author), van der Steen, J.L.P.J. (author), Groeseneken, G. (author), Heremans, P. (author)

In this study, we report high-quality amorphous indiunrv-galiium-zinc-oxide (a-IGZO) thinfilm transistors (TFTs) fabricated on a polyethylene naphthalate foil using a new back-channel-etch (BCE) process flow. The BCE flow allows a better scalability of TFTs for high-resolution backplanes and related circuits. The maximum processing temperature...

article 2014

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Organic imager on readout backplane based on TFTs with cross-linkable dielectrics

Malinowski, P.E. (author), Vicca, P. (author), Willegems, M. (author), Schols, S. (author), Cheyns, D. (author), Smout, S. (author), Ameys, M. (author), Myny, K. (author), Vaidyanathan, S. (author), Martin, E. (author), Kumar, A. (author), van der Steen, J.L. (author), Gelinck, G.H. (author), Heremans, P. (author)

We report on the fabrication of imagers based on organic semiconductors both in the photodiode layer and in the readout backplane. The photodiode is based on evaporated ultrathin (<100 nm) stack of SubPc/C60, sensitive in the wavelength range between 300 and 650 nm. The readout circuit is a switch matrix fabricated with a solution processed...

article 2014

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Flexible low temperature solution processed oxide semiconductor TFT backplanes for use in AMOLED displays

Cobb, B. (author), Rodriguez, F.G. (author), Maas, J. (author), Ellis, T. (author), van der Steen, J.L. (author), Myny, K. (author), Smout, S. (author), Vicca, P. (author), Bhoolokam, A. (author), Rockelé, M. (author), Steudel, S. (author), Heremans, P. (author), Marinkovic, M. (author), Pham, D.V. (author), Hoppe, A. (author), Steiger, J. (author), Anselman, R. (author), Gelinck, G.H. (author)

AMOLED backplanes were fabricated on both rigid glass and flexible plastic substrates using a solution processed oxide semiconductor processed at temperatures <250C with mobilities greater than 2 cm2/Vs. The backplanes were integrated onto a thin film moisture barrier and QQVGA AMOLED displays were successfully fabricated. cop. 2014 Society for...

article 2014

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Flexible AMOLED display and gate-driver with self-aligned IGZO TFT on plastic foil

Nag, M. (author), Obata, K. (author), Fukui, Y. (author), Myny, K. (author), Schols, S. (author), Vicca, P. (author), Ke, T.H. (author), Smout, S. (author), Willegems, M. (author), Ameys, M. (author), Bhoolokam, A. (author), Muller, R. (author), Cobb, B. (author), Kumar, A. (author), van der Steen, J.L. (author), Ellis, T. (author), Gelinck, G.H. (author), Genoe, J. (author), Heremans, P. (author), Steudel, S. (author)

We present a QQVGA (160times120 with 3 sub-pixel) top-emitting AMOLED display with 85ppi resolution using a self-aligned (SA) IGZO TFT backplane on polyimide-foil. The back plane process flow is based on a 5 layer photolithography process. The aperture ratio of the top-emitting OLEDs is approx. 25%. For operation at 6 V supply voltage (VDD), the...

article 2014

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30.1 8b thin-film microprocessor using a hybrid oxide-organic complementary technology with inkjet-printed P2ROM memory

Myny, K. (author), Smout, S. (author), Rockelé, M. (author), Bhoolokam, A. (author), Ke, T.H. (author), Steudel, S. (author), Obata, K. (author), Marinkovic, M. (author), Pham, D.V. (author), Hoppe, A. (author), Gulati, A. (author), Rodriguez, F.G. (author), Cobb, B. (author), Gelinck, G.H. (author), Genoe, J. (author), Dehaene, W. (author), Heremans, P. (author)

We present an 8b general-purpose microprocessor realized in a hybrid oxide-organic complementary thin-film technology. The n-type transistors are based on a solution-processed n-type metal-oxide semiconductor, and the p-type transistors use an organic semiconductor. As compared to previous work utilizing unipolar logic gates [1], the higher...

conference paper 2014

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Full color flexible top-emission AMOLED display on polyethylene naphthalate (PEN) foil with metal oxide TFTs backplane

Fukui, Y. (author), Shibata, M. (author), Tanaka, Y. (author), Okumoto, K. (author), Morita, K. (author), Otake, K. (author), Tripathi, A.K. (author), van der Putten, B. (author), van der Steen, J.L. (author), Tempelaars, K. (author), van Leuken, L. (author), Li, F. (author), Yakimets, I. (author), Gelinck, G.H. (author), Myny, K. (author), Smout, S. (author), Willegems, M. (author), Schols, S. (author), Steudel, S. (author), Genoe, J. (author), Heremans, P. (author)

We have developed a full color flexible top-emission AMOLED display with 80 ppi resolution using In-Ga-Zn-O TFT backplane on PEN foil under the maximum process temperature of 150 oC. Notwithstanding the low processing temperature, the TFTs with SiOx passivation layer show high reliability with VTH shift of less than 0.2 V at 10,000 seconds under...

article 2013

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Low-temperature IGZO TFT backplane and its application in flexible AMOLED displays on ultrathin polymer films

van der Steen, J.L.P.J. (author), Tripathi, A.K. (author), Maas, J.P.V. (author), van Diesen-Tempelaars, K. (author), van Leuken, L.B. (author), de Haas, G.J.A.J.F. (author), van der Putten, J.B.P.H. (author), Yakimets, I. (author), Li, F.M.W. (author), Ellis, T.H. (author), van Mol, A.M.B. (author), Gelinck, G.H. (author), Vicca, P. (author), Smout, S. (author), Ameys, M. (author), Huei Ke, T. (author), Steudel, S. (author), Nag, M. (author), Schols, S. (author), Genoe, J. (author), Heremans, P. (author), Fukui, Y. (author), Green, S. (author)

We present a low-temperature metal oxide transistor backplane technology using PECVD dielectrics. We show successful integration of the backplane in flexible 200ppi AMOLED displays on ultrathin polymer films. The displays are encapsulated with a thin-film barrier and the total stack thickness is less than 150μm.

conference paper 2013

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Design and realization of a flexible QQVGA AMOLED display with organic TFTs

Steudel, S. (author), Myny, K. (author), Schols, S. (author), Vicca, P. (author), Smout, S. (author), Tripathi, A.K. (author), van der Putten, B. (author), van der Steen, J.L. (author), van Neer, M. (author), Schütze, F. (author), Hild, O.R. (author), van Veenendaal, E. (author), van Lieshout, P. (author), van Mil, M. (author), Genoe, J. (author), Gelinck, G.H. (author), Heremans, P. (author)

article 2012