Organic Semiconductor Optoelectronics.

Organic Semiconductor Optoelectronics.

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  Ifor D. W.Samuel1, P. Manousiadis1, H. Chun2, A.K. Bansal1, H. Nguyen1 A. McNeill1, J. Ferguson3, S. Ibbotson3, A. Kanibolotsky4, P. Skabara4, M. Dawson5, D. O’Brien2, H. Haas6 and G.A. Turnbull1 1. Organic Semiconductor Centre, University of St Andrews 2. Communication Research Group, University of Oxford 3. Ninewells Hospital, Dundee 4. Pure and Applied Chemistry Department, University of Strathclyde 5. Institute of Photonics, University of Strathclyde 6. Photonic Materials and Devices Group, University of Edinburgh Photo: A. Thompson Organic Semiconductor Optoelectronics
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  Ifor Samuel, Universityof St Andrews Outline Introduction - light, optoelectronics - organic semiconductors New applications - in medicine - in visible light communication - in sensing www.google.co.uk Dr. Paul Shaw
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  Ifor Samuel, Universityof St Andrews Light Dr Dimali Vithanage www.scotlandforgolf.co.uk www.space.com en.wikipedia.org
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  Ifor Samuel, Universityof St Andrews Light Communication Display Dr Dimali Vithanage en.wikipedia.org
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  Ifor Samuel, Universityof St Andrews Semiconducting Polymers C C C C C C C C C C H H H H H HHHHH C C C C C Conjugated polymers can conduct electricity polyacetylene Actually semiconductors Heeger, MacDiarmid, Shirakawa, Nobel prize 2000
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  Ifor Samuel, Universityof St Andrews Organic Semiconductors Conjugated molecules Novel semiconductors Easy to process Can tune properties Can emit light Flexible 6
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  Ifor Samuel, Universityof St Andrews Semiconductor Devices Transistors Light-emitting diodes Solar cells Light sensors Lasers [1] Photo of organic solar cell from xpsolar.com
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  Ifor Samuel, Universityof St Andrews Organic Light-Emitting Diode (OLED) metal contact organic semic. transparent contact substrate - + - - ++ + - Light-emitting diode (LED) Tang and van Slyke: Small Molecules Burroughes, Bradley, Friend: Conjugated polymers
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  Ifor Samuel, Universityof St Andrews Examples of OLED Displays LG display Dynamic lighting Samsung flexible phone LG OLED curved TV LG OLED rolled TV http://freshome.com http://gadgets.ndtv.com http://www.cnet.com http://oled-news.blogspot.co.uk http://mtnblog.co.za
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  University of StAndrews 10 Organic Semiconductor Centre Organic Semiconductor Centre Visible light communication OLEDsLasers OPV Biophotonics Sensing Photophysics/materials
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  Ifor Samuel, Universityof St Andrews Outline Biophotonic applications Skin cancer treatment Muscle contraction sensor Visible light communication Polymer Laser Sensors G.E.
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  12 Ifor Samuel, Universityof St Andrews Trends in Medicine Continuous monitoring Ambulatory monitoring/treatment Optoelectronic devices non-invasive Conjugated polymers Enable thin, flexible devices Wearable devices for monitoring and treatment Wearable Devices for Biology and Medicine www.amazon.co.uk www.ece.villanova.edu curaderm.olmifon.net
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  13 Skin Cancer Treatment ofskin cancer with light • 15% of UK, 40% of American and 75% of Australian population develop a skin cancer during their life time • 98,000 people are diagnosed with non-melanoma skin cancer each year in the UK • Around 90% of the tumours are on the face and neck, surgery can be complex and leave scars • 491 deaths each year in the UK from untreated non- melanoma skin cancer Ifor Samuel, University of St Andrews
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  14Ifor Samuel, Universityof St Andrews Photodynamic Therapy (PDT) of Skin Cancer Illumination of tumour region with high intensity light source for 20 minutes Presence of light causes PP9 to produce singlet Oxygen leading to local cellular destruction within the tumour only Application of ALA or Metvix cream at tumour site ALA or Metvix metabolised to Light sensitive Protoporphyrin 9 only within the tumour
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  15 Conventional PDT Ifor Samuel,University of St Andrews
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  BCC before &after PDT x3
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  17Ifor Samuel, Universityof St Andrews Potential of OLEDs for PDT • Uniform illumination • Lightweight - can be worn • Allows low intensity/long treatment – Reduced pain, increased effectiveness • Low cost - disposable – Attractive for hygiene – Widens access to PDT • Simple wearable power supply • Scope for ambulatory treatment1 – At work – At home 1. Moseley et al Brit. J. Derm. 154, 747 (2006)
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  Ifor Samuel, Universityof St Andrews 18 Device Applied Device Worn During Normal Daily Activities Device Disposed Wearable Organic Optoelectronic Source for PDT OLED-PDT BioEL 2015, Kirchberg Ifor Samuel, University of St Andrews
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  19Ifor Samuel, Universityof St Andrews OLED PDT: Before and After Before Treatment After Treatment Pilot study Attili et al Brit. J. Derm. 161, 170 (2009)
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  20Ifor Samuel, Universityof St Andrews PDT Pain Results • Ambulatory PDT provides a large reduction in pain for most patients • 50% reported pain score ≤ 2 • In a preliminary study, 16/19 patients that used both conventional and ambulatory PDT, preferred ambulatory. 1 1. Ibbotson et al, Photoderm. Photoimmun. & Photomed., 28, 235
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  21Ifor Samuel, Universityof St Andrews Ambulatory PDT Trial Results and Benefits • Trial Results at 12 month follow-up • 67 patients with 90 lesions (42 BCC, 47 Bowens, 1 AK) • 80 clear, 10 partial response • 89% clearance at 12 months, compared to 70-100% for conventional PDT1. • Achieved with one tenth the intensity for ten times as long • Avoids pain • Ambulatory treatment demonstrated • More comfortable • Possibility of treatment at GP or home • Potential to be low cost, disposable • Lower intensity for longer time avoids pain • Plus all the benefits of regular PDT.
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  Current Prosthetic Sensors Mechanical Connection Signal Connection ElectromyographySensors Piezo-cable Sensors Piezo-thin film Sensors Back force Sensors Drawbacks of Electrical based sensors - EM interference - Painful due to needles - Immune response We can solve the issues by Optical Sensors Optical Flexible Muscle contraction sensor www.zeitnews.org/life-sciences 23 Ifor Samuel, University of St Andrews
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  • Muscles areintrinsically fibrous • Light scattering by the muscle is anisotropic • Fibre Aspect Ratio changes when muscle is contracted Working principle of optical sensor: • Changes in amount of scattering signals contraction 24 Ifor Samuel, University of St Andrews
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  Sensor implementation:  Shinelight into muscle – light is scattered in all directions through the muscle  Place four photodiodes on vertices of a square round source Subtract the parallel and perpendicular photocurrents When muscle is contracted more light reaches the perpendicular photodiodes – causes a change in output Use amplifier to give output voltage indicating muscle contraction 25 Ifor Samuel, University of St Andrews
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  Flexible OLED/OPD Fabrication ITO PETor Glass PEDOT Active layer Ca/Al 26 PTB7 PCBM(C70) OLED Organic photodiodes SPIE 2016, San Diego Ifor Samuel, University of St Andrews
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  Flexible Sensor; Typesof Muscle Contraction • Isotonic contraction – constant force • Isometric contraction – constant length 27 Ifor Samuel, University of St Andrews
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  Optical Signal forMuscle Contractions • Isotonic and isometric contractions can be obviously distinguished • Blood depletion and refilling detected Ifor Samuel, University of St Andrews 28
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  Isometric and IsotonicMuscle Contraction of Biceps Ifor Samuel, University of St Andrews Control of Robotic Arm by Muscle Contraction Sensor
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  Isotonic Muscle Contractionof Deltoid Control of Robotic Arm by Muscle Contraction Sensor Ifor Samuel, University of St Andrews
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  University of StAndrews Vision of VLC HHI, ExtremeTech Collaboration with D. O’Brien, H. Haas, M. Dawson
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  University of StAndrews VLC principles Data in Data out VLC principles  Data from the transmitter side are sent to the receiver side by light in free space.  The light’s properties (e.g. intensity, phase, signal frequency) are modulated to care information.  The driving signal is voltage. VLC principle Tx Transmitter Receiver GaN LED: τ≈10 nsec Wavelength Converter Phosphor: τ≈1 μsec OSC: τ <10 nsec Phosphor bottleneck  Phosphor-based LEDs: blue LED + Yellow phosphor  VLC bottleneck: 𝜏 𝑌𝐴𝐺:𝐶𝑒 ≫ 𝜏 𝐺𝑎𝑁.
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  University of StAndrews Materials for Colour Conversion Materials requirements  Absorption at 450 nm  High solid state PL quantum yield (>50%)  Short radiative lifetime (<5 ns, preferably <2 ns)  Emission across visible  Photostable 33
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  University of StAndrews Materials for Colour Conversion - Lifetime 34 0 10 20 30 40 50 10 100 1000 10000 PLintensity(counts/s) Time (ns) CL-827 Inorganic Phosphor: Y3Al5O12:Ce3+ Organic Semiconductors CdSe 600 0 10 20 30 40 50 10 100 1000 10000 PLintensity(counts/s) Time (ns) CL-827 CdSe QD 0 10 20 30 40 50 10 100 1000 10000 PLintensity(counts/s) Time (ns) CL-827 CdSe QD Y-B3 0 10 20 30 40 50 10 100 1000 10000 PLintensity(counts/s) Time (ns) CL-827 CdSe QD Y-B3 SY 0 10 20 30 40 50 10 100 1000 10000 PLintensity(counts/s) Time (ns) CL-827 CdSe QD Y-B3 SY BBEHP-PPV
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  University of StAndrews Bandwidth of comm. channel Bandwidth of communication channel  The data rate is proportional to BW of the system.  Range of frequencies available to carry signals.  Αttenuation of the amplitude a(ω) of the received signal normalised to a(ω=0). 0 0.2 0.4 0.6 0.8 1 0 0.1 0.2 0.3 a(ω)/a(ω=0) Frequency (GHz) Βandwidth Schematic of setup for BW&DR measurement Bandwidth measurements 0 20 40 60 80 100 -5 -4 -3 -2 -1 0 T4BT-YB3 Super Yellow BBEHP-PPV CL-840 Y-B3 Attenuation(dB) Frequency (MHz)
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  University of StAndrews White VLC Record Data Rates 0.00001 0.0001 0.001 0.01 0.5 1.5 2.5 BER Gb/s White VLC @ 3 cm using SY solution White VLC @ 2 m using SY film Use high BW yellow PL material for white VLC  Dichromatic white light was produced  Orthogonal frequency-division multiplexing was used.  Record Data Rates for White VLC were recorded Bit Error Rates vs Data Rates using OFDMWhite VLC@2m White VLC@3cm µLED@2m H Chun et al, PTL (2014), LED provided by Strathclyde University, M. Dawson et al.
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  University of StAndrews Organic Semiconductors in VLC HHI, ExtremeTech Colour converters OLEDs Directional LEDs Luminescent concentrators OPVs
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  Organic Semiconductor Lasers PhotoG. Tsiminis
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  University of StAndrews 39 Distributed Feedback Lasers 2st order diffraction - feedback 1st order diffraction- output coupling 2st order diffraction - feedback Periodic waveguide structures “reflect” waveguide modes Beff mn 2
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  University of StAndrews 40 Laser application: Explosive sensing  Organic semiconductors: photophysical interaction for sensing  Main explosives in land mines: TNT, DNT, DNB etc.  Nitroaromatic compounds are strongly electronegative  Presence of nitroaromatic molecule causes electron transfer and quenches light emission TM Swager, Chemical Reviews 107 (2007)
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  University of StAndrews 41 Laser vs PL sensing 0 100 200 300 0.6 0.8 1.0 Laser Sensing Normalized Emission(a.u.) Time (s) PL Sensing Laser sensing 40% quenched @ 1 min PL sensing 34% quenched @ 5 min
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  Ifor Samuel, Universityof St Andrews Conclusions Background Photo: Edward Simpson, CC-BY-SA • Organic semiconductors – processable, tuneable optoelectronic materials • Distinctive properties enable new applications • Wearable Organic Optoelectronics for Medicine • Skin cancer treatment by PDT • Muscle contraction sensor • Visible light communication • Record data rate for white VLC • Polymer Laser Sensor • Can detect explosives, drugs
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  Ifor Samuel, Universityof St Andrews OSC group
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  University of StAndrews ERPOS 2017 Electronic and Related Processes in Organic Solids  Long-running (since 1974) organic electronics conference  July 9-13, 2017 www.erpos.org 44