Time-Resolved Transport of Electrons and Holes in Conjugated Polymers

1999 ◽  
Vol 561 ◽  
Author(s):  
D. Pinner ◽  
R. H. Friend ◽  
N. Tessler
Keyword(s):  
Conjugated Polymers ◽  
Temporal Evolution ◽  
Exponential Tail ◽  
Time Resolved ◽  
Light Emitting ◽  
Turn On ◽  
Initial Rise ◽  
Order Of Magnitude ◽  
Slow Rise ◽  
Polymer Light Emitting Diodes

ABSTRACTDetailed experimental and theoretical analysis of the pulsed excitation of polymer light emitting diodes is presented. We find a set of universal transient features for different device configurations which can be reproduced using our phenomenological numerical model. We find that the temporal evolution of the electroluminescence can be characterised by five main features: i) a delay followed by; ii) fast initial rise at turn-on followed by; iii) a slow rise (slower by at least one order of magnitude); iv) fast modulation (<15ns, unresolved) at turn-off followed by v) a long-lived exponential tail. We suggest a method for extracting mobility values which is found to be compatible with CW drive schemes. Mobilities for holes and electrons are extracted for a poly(p-phenylenevinylene) co-polymer and poly(di-octyl fluorene).

&[mu]-Watt Enhanced Electroluminescent Power of Silicon Nanocrystal Light-Emitting Diodes Made on Nano-Scale Silicon-Tip-Array Substrate

2007 ◽  
Vol 989 ◽  
Author(s):  
Gong-Ru Lin ◽  
Chun-Jung Lin
Keyword(s):  
Light Emitting Diode ◽  
Optical Power ◽  
Oxide Semiconductor ◽  
Si Substrate ◽  
Light Emitting ◽  
Pillar Array ◽  
Turn On ◽  
Air Interface ◽  
Order Of Magnitude ◽  
Etching Mask

AbstractA Si nanocrystal based metal-oxide-semiconductor light-emitting diode (MOSLED) on Si nano-pillar array is preliminarily demonstrated. Rapid self-aggregation of Ni nanodots on Si substrate covered with a thin SiO2 buffered layer is employed as the etching mask for obtaining Si nano-pillar array. Dense Ni nanodots with size and density of 30 nm and 2.8×10 cm-2, respectively, can be formatted after rapid thermal annealing at 850°C for 22 s. The nano-roughened Si surface contributes to both the relaxation of total-internal reflection at device-air interface and the Fowler-Nordheim tunneling enhanced turn-on characteristics, providing the MOSLED a maximum optical power of 0.7 uW obtained at biased current of 375 uA. The optical intensity, turn-on current, power slope and external quantum efficiency of the MOSLED are 140 μW/cm2, 5 uA, 2+-0.8 mW/A and 1×10-3, respectively, which is almost one order of magnitude larger than that of a same device made on smooth Si substrate.

Synthesis of New Blue Anthracene-based Conjugated Polymers and Their Applications in Polymer Light-Emitting Diodes

2011 ◽  
Vol 212 (11) ◽  
pp. 1100-1108 ◽  
Author(s):  
Hung-Min Shih ◽  
Cheng-Jui Lin ◽  
Shin-Rong Tseng ◽  
Chih-Hung Lin ◽  
Chain-Shu Hsu
Keyword(s):  
Conjugated Polymers ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Polymer Light Emitting Diodes

Characterization of Minority-Carrier Hole Transport in Nitride-Based Light-Emitting Diodes with Optical and Electrical Time-Resolved Techniques

2004 ◽  
Vol 831 ◽  
Author(s):  
R. J. Kaplar ◽  
S. R. Kurtz ◽  
D. D. Koleske ◽  
A. A. Allerman ◽  
A. J. Fischer ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Minority Carrier ◽  
Hole Transport ◽  
Optical Measurements ◽  
Hole Density ◽  
Transport Parameters ◽  
Two Phase ◽  
Time Resolved ◽  
Light Emitting ◽  
Order Of Magnitude

ABSTRACTForward-to-reverse bias step-recovery measurements were performed on In.07Ga.93N/GaN and Al.36Ga.64N/Al.46Ga.54N quantum-well (QW) light-emitting diodes grown on sapphire. With the QW sampling the minority-carrier hole density at a single position, distinctive two-phase optical decay curves were observed. Using diffusion equation solutions to self-consistently model both the electrical and optical responses, hole transport parameters τp = 758 ± 44 ns, Lp = 588 ± 45 nm, and μp = 0.18 ± 0.02 cm2/Vs were obtained for GaN. The mobility was thermally activated with an activation energy of 52 meV, suggesting trap-modulated transport. Optical measurements of sub-bandgap peaks exhibited slow responses approaching the bulk lifetime. For Al.46Ga.54N, a longer lifetime of τp = 3.0 μs was observed, and the diffusion length was shorter, Lp ≈ 280 nm. Mobility was an order of magnitude smaller than in GaN, μp ≈ 10−2 cm2/Vs, and was insensitive to temperature, suggesting hole transport through a network of defects.

Lithium salt doped conjugated polymers as electron transporting materials for highly efficient blue polymer light-emitting diodes

2008 ◽  
Vol 93 (24) ◽  
pp. 243302 ◽  
Author(s):  
Fei Huang ◽  
Ping-I Shih ◽  
Michelle S. Liu ◽  
Ching-Fong Shu ◽  
Alex K.-Y. Jen
Keyword(s):  
Conjugated Polymers ◽  
Light Emitting Diodes ◽  
Lithium Salt ◽  
Light Emitting ◽  
Highly Efficient ◽  
Polymer Light Emitting Diodes

scholarly journals Ultraflexible organic photonic skin

2016 ◽  
Vol 2 (4) ◽  
pp. e1501856 ◽  
Author(s):  
Tomoyuki Yokota ◽  
Peter Zalar ◽  
Martin Kaltenbrunner ◽  
Hiroaki Jinno ◽  
Naoji Matsuhisa ◽  
...  
Keyword(s):  
Thin Film ◽  
Human Skin ◽  
Information Technologies ◽  
Industrial Applications ◽  
The Body ◽  
Electronic Components ◽  
Light Emitting ◽  
Order Of Magnitude ◽  
Polymer Light Emitting Diodes ◽  
Organic Photodetectors

Thin-film electronics intimately laminated onto the skin imperceptibly equip the human body with electronic components for health-monitoring and information technologies. When electronic devices are worn, the mechanical flexibility and/or stretchability of thin-film devices helps to minimize the stress and discomfort associated with wear because of their conformability and softness. For industrial applications, it is important to fabricate wearable devices using processing methods that maximize throughput and minimize cost. We demonstrate ultraflexible and conformable three-color, highly efficient polymer light-emitting diodes (PLEDs) and organic photodetectors (OPDs) to realize optoelectronic skins (oe-skins) that introduce multiple electronic functionalities such as sensing and displays on the surface of human skin. The total thickness of the devices, including the substrate and encapsulation layer, is only 3 μm, which is one order of magnitude thinner than the epidermal layer of human skin. By integrating green and red PLEDs with OPDs, we fabricate an ultraflexible reflective pulse oximeter. The device unobtrusively measures the oxygen concentration of blood when laminated on a finger. On-skin seven-segment digital displays and color indicators can visualize data directly on the body.

Sign in / Sign up

Export Citation Format

Share Document