Report

Teaser, summary, work performed and final results

Periodic Reporting for period 3 - ROLL-OUT (High-performance, Flexible, AUTOnomous Systems manufactured with Unique, Industrial ROLL-to-roll equipments)

Teaser

1. Indium-free oxide transistors fabricated on flexible substrates, exhibiting mobility above 20 cm2/Vs with excellent stability under light and negative gate bias stress (ΔVT

Summary

1. Indium-free oxide transistors fabricated on flexible substrates, exhibiting mobility above 20 cm2/Vs with excellent stability under light and negative gate bias stress (ΔVT<0.5 V after 1h stress).
2. Roll-to-roll (R2R) printed integrated circuits with operational amplifier and differential amplifier based on In-free semiconductor oxide transistors.
3. Pressure sensors printed in a R2R process that can detect changes in the ranges 0.05–20 kg/cm2 with more than 10 million actuations after integration into smart autonomous systems.
4. Si temperature sensors processed by printing techniques in ambient air environment.
5. Printed, solid-state batteries with capacity of 150 mAh/gm (active material) and cell-voltage of 2 V.
6. Development of sputtering and atomic-layer deposition into a R2R system for application in large-area electronics manufacturing.
7. A R2R-fabricated, flexible autonomous system with integrated circuits, sensors and power source.
8. A door-handle demonstrator for automotive applications will be fabricated with the proposed TOLAE technology until the end of the project.
9. Large area distributed pressure sensors will be integrated between different layers of car seat textiles for measuring occupancy and weight of the passenger.
10. An autonomous (i.e. battery driven) multi-sensor application will be developed for beverage packaging independently indicating:
a. a loss of under-pressure upon unintended or intended breaking of the sealing (pressure sensors)
b. the fill level of opaque bottles (capacitive sensors)
c. The temperature of the drink to support the user decision for or against consumption.

Work performed

The main results achieved are:
• R1: The construction and testing of the three demonstrators: smart bottle, car window control and car seat sensor array that were presented in Semicon 2017
• R2: Lab-scale sputtered indium-free zinc-tin oxide (ZTO) thin-film transistors (TFTs) fabricated on flexible PEN foil with maximum processing temperature of 180 °C having comparable performance to state-of-the-art indium-gaIlium-zinc oxide (IGZO) TFTs: µFE≈5 cm2/Vs, Von≈0 V, On/Off ratio >106, S≈0.2 V/dec. Under negative bias illumination stress threshold voltage only shifts -1 V (λ=420 nm, VGS=-4 V, during 1 h), being the shift fully recoverable after ≈10 min.
• R3: Design, simulation, layout extraction, fabrication and characterization of an integrated circuit for the readout of fill-level and temperature sensing in smart bottles, entirely based on oxide TFTs. The system has a significant complexity (>180 transistors, divided in analogue and digital blocks), showing the potential of oxide electronics to go well beyond the conventional switching and current driver elements of displays.
• R4: Completion of three fully roll-to-roll process for thin film transistors and circuits combining printing, evaporation, lift-off, sputtering and ALD fabrication steps at three different partners. Good performance has not been achieved due to the small number of trials not being enough to eliminate all the problems in substrate scratching, layer cracking as well as mechanical and thermal stress. However, the overall process compatibility has been demonstrated and new process steps have been verified in the patterning of the layers.
• R5: To increase the number of printed layers, usage of silver nanoparticle ink for S/D contacts of oxide TFT has been developed based on interface modification with PEI.
• R6: A printable all-organic proton battery has been presented. The battery is completely devoid from metals and can, in principle, be disposed of by combustion.

The objectives of the project are evaluated as follows:
1. Industrially relevant level of performance met, not fully the objective (see R2 above).
2. Partially met. TFTs integrating ALD-Al2O3 (Picosun) and sputtered-ZTO (Polyteknik) were successfully fabricated on 4” PEN substrates with maximum temperature of 150 °C. After multiple runs between UNINOVA, Picosun and Polyteknik for process tuning, performance metrics were µFE≈2 cm2/Vs, Von≈0 V, On/Off ratio >106, S≈0.6 V/dec. Then, TFTs and circuits have been fabricated using R2R processing for all the steps. Three processing rounds have been completed. Each multi-site processing trial has taken several months and has faced unforeseen challenges (See R4 above)
3. Met. Pressure sensors technology, mostly based on interdigitated metal electrodes with several functional layers on top have been scaled up to R2R processes.
4. Met by replacement solutions, namely TFT based temperature sensing circuits.
5. The battery objectives have been partially met. The presented battery relies on proton cycling and provides capacities in the range of 100-120 mAh/g active material. A printable all-organic battery and batteries with solid separators have thus been developed within the project and the capacity is close to the one specified. The voltage requirements have proven difficult to meet due to difficulties in altering the redox potential of individual components through chemical modifications without compromising material stability and thorough theoretical and experimental studies on has been undertaken to solve this issue.
6. Exceeded. The project has demonstrated all the R2R processing steps for a substrate width of 30 cm.
7. Not met. A flexible autonomous system was implemented using sputtering as a S2S process for the smart bottle demonstrator, using lab-scale processes. However, yield and uniformity issues of the lab-scale processing tools have prevented the whole system based on oxide electronics to work although al

Final results

As the objectives of the project were set to go beyond the state of the art, see above for the analysis on progress with respect to the objectives.

The project has demonstrated new product concepts in three different application areas that are the smart packaging (ILAB bottle for consumer drinks sensing the fill level and temperature), car interior (Maier flexible sensors for window control in door handle) and smart textiles (FOV car-seat pressure sensor). Cost efficient commercializations of these are expected to be enabled by the project large-area processing developments that expand the availability of different processing techniques in roll-to-roll fabrication. Printed electronics and flexible thin-film electronics that these developments are linked to represent emerging markets with significant growth potential as regularly illustrated by market analysis companies.

Website & more info

More info: http://www.roll-out-2020.eu.