Organic and Printed Electronics

Organic and printed electronics device is a kind of electronic component that converts light energy into electric energy depending on the photoelectric effect, which is the basis of all photoelectric detection devices and photocells. It was mainly emitted by photoelectrons from metals or inorganic semiconductors, photoconductive effect and photovoltaic effect to achieve this function. In recent years, devices based on photoelectrochemical conversion represented by dye-sensitized solar cells have become a research hotspot. Organic and printed electronics materials have a series of excellent properties and show superiority in many aspects. Organic and printed electronics materials have many remarkable characteristics, such as diverse types and structures, properties that can be adjusted by structural modification, simple synthesis process, low preparation cost, easy to be fabricated on different substrates, and can be used for the preparation of flexible electronic devices.

Application:

Organic and printed electronics materials can show different application value to different driving factors, such as light, electricity, sound, heat, chemistry and so on, and these properties are closely related to the molecular structure of organic electronic materials. Therefore, a large number of new materials with expected functions can be obtained by designing and tailoring the molecular structure of organic electronic materials. For example, organic electroluminescent materials used in display technology. Organic semiconductor materials used in field-effect transistors; Organic photovoltaic materials used for energy storage; Photothermal photoconductive materials used in information storage and information transmission; Conductive polymer materials used in electrostatic protection, electromagnetic radiation protection and so on.

• Organic semiconductor material：It refers to a class of organic compound materials whose conductivity is between organic insulators and organic conductors. Common organic semiconductor materials such as silicon semiconductors can be used in optoelectronics. Some researchers have developed a new material that belongs to the carbon nitride family: triazine-based graphite carbon nitride (TGCN). It is a kind of semiconductor that can be highly adapted to the application of optoelectronics. TGCN is the best candidate to replace common inorganic semiconductors such as silicon and their key dopants, some of which are rare elements. It promotes the production of large-scale and simplified electronic devices.

Figure 1. The structure of triazine Cornerstone Ink Phase carbon Nitride(TGCN)

• Photoconductive material: It refers to a kind of material whose resistivity changes with light intensity, which can usually be ultraviolet light, visible light and infrared light. Photoconductive materials are divided into two categories: inorganic photoconductive materials and organic photoconductive materials. Inorganic photoconductive materials include selenium, selenium-tellurium alloy, cadmium sulfide, zinc oxide, etc. Organic photoconductive materials include polyvinylcarbazole, some phthalocyanine complexes, some azo compounds and some squaline compounds. Photoconductive materials are widely used in electrophotography (photocopying technology). For example, selenium can be used in photocopiers as selenium cartridges. Some organic photoconductive materials are sensitive to near-infrared light and can be used in laser printers.
• Conductive polymer material: It is a kind of polymer material with conductive function (including semi-conductivity, metal conductivity and superconductivity) and conductivity above 10^-6S/m. The first high conductivity polymer material is iodine-doped polyacetylene, and then polypyrrole, poly (p-phenylene), polyphenylene sulfide, polyaniline and other conductive polymer materials have been developed. In addition, conductive polymer materials have good conductivity and electrochemical reversibility, so they can be used as electrode materials for rechargeable batteries.

Figure 2. Flexible and transparent organic solar cells

References:

1. J. J. M. Halls, C. A Walsh(1995).“Efficient photodiodes from interpenetrating polymer networks.” Nature, 376: 498-500
2. G Yu, J. Gao, J. C. Hummelen (1995).”Polymer photovoltaic cells: enhanced efficiencies via a network of internal donor-acceptor heterojunctions.” Science, 270: 1789-1791