Light Emitting Electrochemical Cells as Mixed Ionic Electronic Conductors

1998 ◽  
Vol 548 ◽  
Author(s):  
I. Riess ◽  
D. Cahen

ABSTRACTPolymer electrochemical cells have been reported to emit light. The current and light output increase rapidly with voltage, apparently beyond 2V. The polymer is an ionic conductor as well as an electronic (electron/hole) conductor, i.e. a mixed ionic-electronic conductor (MIEC).The I-V relations are explained here to be those of an MIEC of a particular defect model placed between two ion blocking electrodes. This MIEC defect model assumes a large concentration of mobile ions and small concentrations of electrons and holes. A p and an n region are formed in the MIEC. However, there is no space charge within the MIEC and it stays neutral. The resulting I-V relations are exponential. A good fit to the experimental data is obtained when electrode over-potential and heating of the polymer under current are taken into consideration.

2021 ◽  
Author(s):  
Yanxi Zhang ◽  
Eveline van Doremaele ◽  
Gang Ye ◽  
Tim Stevens ◽  
Jun Song ◽  
...  

Organic mixed ionic-electronic conductors (OMIECs) are central to bioelectronic applications such as biosensors, health monitoring devices and neural interfaces, and have facilitated efficient next-generation brain-inspired computing and biohybrid systems. Most OMIECs are hole-conducting (p-type) materials, while complimentary logic circuits and various biosensors require electron-conducting (n-type) materials too. Here we show an ambipolar mixed ionic-electronic polymer that achieves high on/off ratios with high ambient p- and n- type stability. We highlight the versatility of the material by demonstrating its use as a neuromorphic memory element, an adaptable ambipolar complementary logic inverter, and a neurotransmitter sensor. The ambipolar operation of this material allows for straightforward monolithic fabrication and integration, and opens a route towards more sophisticated complex logic and adaptive circuits.


2014 ◽  
Vol 16 (41) ◽  
pp. 22513-22516 ◽  
Author(s):  
Ilan Riess

The interpretation of Onsager cross transport coefficients measured in mixed ionic electronic conductor (MIEC) oxides is examined.


2008 ◽  
Author(s):  
Henk Bolink ◽  
Rubén D. Costa ◽  
Enrique Orti ◽  
Michele Sessolo ◽  
Stefan Graber ◽  
...  

2003 ◽  
Vol 764 ◽  
Author(s):  
X. A. Cao ◽  
S. F. LeBoeuf ◽  
J. L. Garrett ◽  
A. Ebong ◽  
L. B. Rowland ◽  
...  

Absract:Temperature-dependent electroluminescence (EL) of InGaN/GaN multiple-quantum-well light-emitting diodes (LEDs) with peak emission energies ranging from 2.3 eV (green) to 3.3 eV (UV) has been studied over a wide temperature range (5-300 K). As the temperature is decreased from 300 K to 150 K, the EL intensity increases in all devices due to reduced nonradiative recombination and improved carrier confinement. However, LED operation at lower temperatures (150-5 K) is a strong function of In ratio in the active layer. For the green LEDs, emission intensity increases monotonically in the whole temperature range, while for the blue and UV LEDs, a remarkable decrease of the light output was observed, accompanied by a large redshift of the peak energy. The discrepancy can be attributed to various amounts of localization states caused by In composition fluctuation in the QW active regions. Based on a rate equation analysis, we find that the densities of the localized states in the green LEDs are more than two orders of magnitude higher than that in the UV LED. The large number of localized states in the green LEDs are crucial to maintain high-efficiency carrier capture at low temperatures.


2020 ◽  
Vol 13 (8) ◽  
pp. 084002
Author(s):  
Yuki Tanaka ◽  
Jiang Pu ◽  
Taishi Takenobu

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