Large Area Electronics: Challenges and Opportunities Going from Lab to Fab and Device to Product Prof. Donald Lupo Department of Electronics and Communications Engineering Tampere University of Technology Tampere, Finland donald.lupo@tut.fi 1
Outline Large area electronics: what are we talking (and not talking) about? Where is it going (OE-A Roadmap)? Key challenges: Red brick walls No one buys a transistor system integration Some ways to go Print when it makes sense: simple circuits, heterogenous integration, energy harvesting and distributed electronics and well-being Moving towards fully printed- the Thin Film story Large area an opportunity for the UK to create value? 2
What are we talking about today? A lot of the multibillion dollar electronics business is large area Si fabs have moved to larger wafers while also going to smaller features (ca 11 nm in 2015) Displays including TFT backplanes now made on 2-3 m size substrates We re talking here about something else Larger structures and patterning processes for these (printing, coating, embossing..) Flexible and large area devices (displays, OPV, OLED lighting ) Flexible, lightweight, low cost, multifunctional systems Also called TOLAE 3
What we ve been saying: A Future Multi-Billion $ Market Organic electronics enables new applications and opens new markets 2012: 8 Bn US$, predominantly by OLED displays Potential for a 50 Bn US $ market within the next 10 years driven by lighting, displays, OPV, logic, memory/rfid, sensors So- when will we realise this potential? And where? For this we need roadmapping 4
Roadmapping: The OE-A Roadmap, Fifth Edition Core activities of OE-A Aims See where the field is going Identify key opportunities and, especially, challenges Updated every 1-2 years, current 5 th edition published 2013 Based on expertise of OE-A member organisations and discussions in the community over 50 core team members in the last round Application areas: OPV, flexible displays, OLED lighting, electronics and components, integrated smart systems Technology teams: materials, substrates, patterning processes Approach: Vision for short, medium and long term products Application and technology parameters needed Compare with linear development Identify predicted trends, and needs for breakthroughs ( red brick walls, term borrowed from Semi roadmap) 5
OE-A Roadmap, Key Messages Organic and printed electronics progresses in an organic growth Commercial products are now appearing in most of the application clusters, more products are in the pilot or test marketing phases Continued organic growth in a number of areas is more likely than a new killer app Heterogeneous integration (organic and Si) and hybrid processing will be important for new products in the short to medium term. Published in the OE-A brochure. More detailed white paper available for download from www.oe-a.org 6
OE-A Roadmap, Key Trends Mobilities of organic semiconductors, conductivity of printed conductors and efficiency of OPV materials continue to increase rapidly Patterning processes are being scaled to smaller dimensions Hybrid processing and heterogeneous integration of printed and silicon based components show promise of leading to new products Flexible, lightweight, mobile electronic products are starting to enter the market, enabled by organic and printed electronics Applications in intelligent packaging and smart textiles are starting to appear 7
Automotive Applications Today Printed antennas Airbag sensors (seats) Electrochromic rear mirrors Electroluminesence: ambient lighting, instrument cluster Printed window defrosters Electrochromic glass roofs Touch displays Switches with OLEDs Printed seat heaters Tomorrow Touch surfaces / MMI OPV for energy harvesting OLED rear lighting OLED interior lights Flexible OLED displays OLED rear mirrors Picture: PolyIC, IEE, Heliatek 8
Smart Textile Applications Today Safety clothing Fashion: Keypads and solar cells integrated, sensors in sports jackets Tomorrow Smart Clothing with Batteries Loudspeakers OPV Lighting Sensors Smart carpets with pressure sensors Textiles for health monitoring: temperature, respiration, blood pressure Seat heaters for cars and furnitures Source: Cetemmsa, Fraunhofer IZM, Hong Kong Polytechnic University 9
Printing / Packaging / Advertising Today Printed Interactive Cards Interactive Journals (Display, PV, batteries LEDs) e.g. Esquire, TV Movie Interactive Pricetags and Smart shelves Interactive posters: electroluminescent, motion sensors Tickets Smart packages with printed lighting elements Tomorrow Smart Labels: e.g. Time- Temperature Indicators Intelligent packaging Interactive newspapers Interactive billboards Printed RFID tags Source: Thin Film, Bauer Media, ISORG, Karl Knauer 10
Healthcare Applications Today Diagnostic electrodes Printed blood glucose test strips Printed flexible electrodes for ECG, EEG, EOG Printed cholesterol test strips Therapeutic electrodes Laboratory analytical electrodes Smart pharmaceutical blister package for field trials Tomorrow Smart Packages to support patient compliance Flexible Displays integrated in package for patient information Anti-counterfeit RFID for logistics Smart clothing with embedded motion and physiological sensors Flexible textile sensors in mattresses to prevent sores Smart patches: light therapy, drug delivery, temperature OLED blankets for phototherapy Source: Holst Centre, Philips, Dura Stick 11
Energy Today Flexible batteries Smart Packaging Mobile and other electronic devices Flexible OPV for consumer goods e.g. bags or backpacks OPV powered keyboard Tomorrow Building Integrated Photovoltaic (BIP) OPV canopy Automotive applications Source: Konarka, Heliatek 12
Lighting Today Designer luminaires Electroluminescence, night lighting, ambient lighting Tomorrow Smart windows with OLEDs Flexible OLED wallpaper Integration in textiles Bags Safety clothing Fashion and sportswear Source: OSRAM 13
Displays Today Electrophoretic displays OLED displays for smart Phones, tablets ereaders OLED TV (55 ) Smart price tags (Electrochromic, e-ink) Tomorrow Flexible color ereader Flexible OLED displays Rollable OLED TV Source: Ella Retail, LG, Samsung 14
Short List of Key Application Parameters Different sets of key parameters for different applications Short list of most important parameters: Complexity of the device Operating frequency of the circuit Lifetime/stability/homogeneity/reliability Operating voltage Efficiency Cost Source: Osram, Holst Centre, Thin Film Electronics 15
Technology: Short List of Key Technology Parameters Mobility / electrical performance (threshold voltage, on/off current) Resolution / registration Barrier properties / environmental stability Flexibility / bending radius Fit of process parameters (speed, temperature, solvents, conditions, vacuum, inert gas atmosphere) Yield ambient Source: CPI 16
Key Challenges / Red Brick Walls Major breakthroughs are absolutely necessary: Materials Charge carrier mobilities of printable commercially available n- and p-type semiconductors above 5 10 cm²/vs Improved processability and reproducibility even more critical Improved environmental stability is needed to enable operation in robust environment Processes Higher resolution, registration and process stability of the patterning processes needed Uniformity over large areas need to be improved High-throughput inline electrical characterization is necessary Encapsulation Flexible, transparent barriers at low cost with improved barrier properties Standards and Regulations Defining new standards which reflects the needs of organic and printed electronics applications 17
Outline Large area electronics: what are we talking (and not talking) about? Where is it going (OE-A Roadmap)? Key trends Key challenges: red brick walls No one buys a transistor system integration Some ways to go Print when it makes sense, Si for the rest: heterogenous integration, energy harvesting and distributed electronics and well-being Moving towards fully printed- the Thin Film story Large area an opportunity for the UK to create value? 18
From the device to the system Scientific literature still very focused on champion materials (mobilities) and devices (efficiency, on/off ratio etc.) But the market for single transistors has gone down significantly in the last 30 years.. People don t buy devices, they buy products that do something they want/need For this you need to integrate different devices to a system, which is non-trivial Different devices with different operating voltages, impedances etc. Circuit design can t just be taken over blindly from Si 19
Organic circuit issues: rectification Fully printed half-wave rectifiers work pretty well even with bad semiconductors But we throw half the RF cycle away The obvious solution : full wave The reality: a full-wave rectifier based on gravure printed PTAA diodes actually delivers less than half-wave due to series resistance May still be useful for low frequencies and need for low ripple voltage For RF harvesting: antenna resonance changed by diode capacitance: the best diodes don t give the most energy (M. Li et al, submitted) If you need more voltage: charge pump circuit may make more sense The circuit has to fit the application AND account for properties of organic devices 5 mm P. Heljo at al., Proceedings MRS, 2012, IEEE Trans. Electron Dev. 60, 870 2013) P. Heljo at al., Organic Electronics 15, 306 (2014) 20
System issues: energy One goal of TOLAE is electronics everywhere : sensors, smart cards, packaging. But what about power? Batteries Can be a cost issue (if not buttons) Are subject to laws concerning disposal and may have safety issues But best energy density Harvesting ambient energy RF: depends on readers/logistics or needs to be able to harvest mobile phone smog Light: optimisation of PV for indoor/low light Piezo: motion harvesting, need improved printable/flexible materials Storage: supercaps can be almost edible and have lower energy density but higher cycle life V capacitor (V) V ASIC (V) 2.0 1.5 1.0 0.5 1.5 1.0 0.5 0.0 printed antenna printed diode Lehtimäki et al., Int. J. Elect. Power and Energy Systems, in press (2014) 2 cm 2, high input 2 cm 2, low input 4 cm 2, high input 4 cm 2, low input 0 2 4 6 8 10 12 Time (h) 21
System issues: uniformity A semiconductor with a mobility of 5 is great So is an on/off ratio of a million A solar cell of 12% An OLED with 80 lm/w But this isn t enough: reliability, reproducibility and uniformity are needed for real products Example display backplane: > 1 million TFTs For e-paper: already need good uniformity For current driven displays (OLEDs) extremely high uniformity needed Sometimes better to sacrifice some mobility for uniformity Example sensors If we want to control and read a sensor with printed circuits, this means analog electronics Still a challenge for printed/organic and a good field for research 22
Outline Large area electronics: what are we talking (and not talking) about? Where is it going (OE-A Roadmap)? Key trends Key challenges: red brick walls No one buys a transistor system integration Some ways to go Print when it makes sense: simple circuits, heterogenous integration, energy harvesting and distributed electronics and wellbeing Moving towards fully printed- the Thin Film story Large area an opportunity for the UK to create value? 23
Heterogenous System Integration Printing can do many things Sensors Lighting elements PV and photodetectors Display elements Energy harvesters Energy storage (batteries and supercaps) Interconnects But when it comes to calculations it can t compete with Si yet One approach- stay away from number crunching, very simple applications Another print the stuff that should be printed, use Si where it s best: heterogenous integration 24
Motivation for Heterogenous Integration Energy 25
Opportunities for Integration 26
Application field electronic skin Using conventional components and designing for stretchability complex multifunctional sensors Fully organic components J. Rogers group, Univ. of illinois T. Someya group, Univ. Tokyo 27
From mixed to fully printed Thin Film Electronics A lot can be done by combining printing and conventional microelectronics and this will be important for some time But the goal eventually is to print everything (form factor, flexibility, cost..) Recent demonstration that this is feasible from Thin Film Electronics and partners: a fully functional temperature sensor tag with memory, logic, battery and display 28
Inherently large area What inherently needs large area? Among others, displays, OLED lighting and OPV The UK seems to be going in the right direction here CDT as founder of PLED displays Recent CPI announcement of display backplanes Start-ups and spin-offs for OPV Keep up the good work and remember: it s how the whole system works. Only nerds will care if it s organic. 29
Summary a few takeaways The TOLAE market is there and growing, even if the big splash stories aren t there OE-A s roadmap has identified opportunities and major challenges these need to be addressed It s not about a device or a mobility think systems and circuits! Remember that organic devices can be different Don t be afraid of heterogenous integration But don t lose the vision of printing either; it will come The UK is doing the right thing with current activities and with this Centre 30