DIY organic LEDs. Scheme, description

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Schemes of radio-electronic and electrical devices

Manufacture of organic oLED LEDs. Encyclopedia of radio electronics and electrical engineering

Free technical library

Encyclopedia of radio electronics and electrical engineering / Ham Radio Technologies

Comments on the article

What is an organic LED? Organic Light-Emitting Diode (oLED) - an organic light-emitting diode, made from organic compounds capable of emitting light when a current is passed.

In this article, we will look at how to make organic oLEDs in a home laboratory with our own hands.

The coordination complex between the transparent tin oxide electrode and the active metal electrode emits light when an external voltage is applied. Coating too thin a layer of [Ru(bipyridine)3](BF4)2-polyvinyl alcohol will result in a short circuit and no light emission; a coating that is too thick will have too high an electrical resistance and will also result in no radiation.

Determine the conductive side of the tin oxide coated glass sample by measuring the resistance with a tester. The final resistance of the conductive side should be 20-30 ohms.

Use double-sided adhesive tape to secure the indium tin oxide coated glass, conductive side out, to a fan at up to 2500 rpm.

Using a cotton swab, apply a solution of [Ru(bipyridine)₃](BF₄)₂- polyvinyl alcohol on the central part of the glass. Rotate the sample at 2500 rpm for 30-60 s, use a protective shield to prevent splashing. Repeat the application 3-4 times, leaving the edges uncovered.

Instead of the preferred rotation coating method, you can use double-sided adhesive tape to attach the indium tin oxide coated glass with the conductive side out to the table surface. Apply a very thin layer of [Ru(bipyridine)₃](BF₄)₂-polyvinyl alcohol on glass. Evaporate the liquid with a heat gun or hair dryer. Repeat the application 3-4 times, leaving the edges uncovered.

Make a stencil. To do this, glue a piece of electrical tape to aluminum foil and pierce a hole in it with a diameter of approximately 3 mm.

Dry the glass with a hair dryer for at least a minute to remove any liquid remaining on the film. The first reason for the failure in the manufacture of organic light emitting diodes oLED is due to insufficient drying of the polymer layer before applying the active metal layer.

Using a cotton swab, apply a liquid alloy of gallium and indium (active metal electrode) through the stencil. Eutectic mixture of 75,5% gallium and 24,5% indium liquid at temperatures above 16,5^оC.

Connect the positive lead of the 4,5V power supply to tin oxide coated glass (not polymer coated). Carefully connect the negative lead to the gallium-indium alloy. In a humid environment, the service life is significantly reduced.

View from the uncoated side of the glass.

Or watch in the dark.

Is this section a diode? What happens if the polarity of the supplied voltage is reversed?

Materials

Ready-made solutions for various preparations:

Place approximately 0,30 g of PVA (polyvinyl alcohol, Aldrich, 36,316-2, average molecular weight 124 - 000) and 186 ml of water in a 000 ml beaker. To dissolve the PVA, cover the beaker loosely with plastic and heat in the microwave several times for 10 seconds until completely dissolved. Do not let the solution boil.

Dissolve approximately 0,035 g of [Ru(bipyridine)₃](BF₄)₂ (synthesis - see article 2) in 3 ml of polyvinyl alcohol solution.

GaIn Eutectic (Eutectic mixture of gallium and indium), Aldrich, 49542-5

Equipment:

Conductive glass (glass 1" x 1" x 2,3 mm TEC 15), Hartford Glass Co, 735 E Water Street, Hartford City, IN 47348 Phone: 765-348-1282
Ohmmeter
2500 rpm fan and power supply: Radio Shack fan 273-243B 12VDC, universal power adapter 273-1662
Double-sided adhesive tape
Stencil made of aluminum foil and electrical tape with a hole of ~3 mm
Cotton swabs
Hairdryer
Power supply 4,5V

Modified by Jason Marmon, George Lisensky, and Wendy deProfetis using the following sources: Frank G. Gao, Allen J. Bard "Semiconductor Organic Light-Emitting Diodes Based on Tris(2,2'-bipyridine)ruthenium(II) Complexes", Journal of American Chemistry Society, 122(30), 7426-7427 (2000); Hanna Sevjan, Sin Muller, Hartmut Rudmann, Michael F. Rabner "The Use of Organic Light-Emitting Electrochemical Thin Film Components in the Study of Materials Science", Journal of Chemical Education, 81(11), 1620 (2004).

Publication: cxem.net

See other articles Section Ham Radio Technologies.

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Artificial leather for touch emulation 15.04.2024

In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>

Petgugu Global cat litter 15.04.2024

Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>

The attractiveness of caring men 14.04.2024

The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>

Random news from the Archive

Blu-ray disc cost 20.02.2006

Panasonic has announced the estimated cost of Blu ray discs (BD), which will soon begin selling in the US.

Americans will be offered four types of new media, each of which will differ not only in features, but also in price: recordable 25-gigabyte single-layer BD - $17 (US); recordable 99 GB dual-layer BD $50; rewritable 42 GB BD $99; rewritable 25 gigabyte BD $24

A regular Blu-ray "blank" is recorded at 24 speed and can later be played on consumer video equipment, personal computers and other devices that can read the new format.

Paying $60 for new media from Panasonic isn't cheap, but you get 25 to 50 GB of free space and increased scratch protection (thanks to inorganic lightfast materials and sensitive film).

Other interesting news:

▪ Growth of the precision farming market

▪ Smart material based on shark skin

▪ Chip for ultra-fast data transmission using light

▪ Biodiesel from chicken bones

▪ Climate weapons against weather anomalies

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Household electrical appliances. Selection of articles

▪ article Occupational health and safety. Crib

▪ How many legs does a centipede have? Detailed answer

▪ article Framework. Legends, cultivation, methods of application

▪ article Miniature radio receiver. Encyclopedia of radio electronics and electrical engineering

▪ article Features of the design of modern tube ultrasonic frequencies. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews