Organic Electronics is a field and realm of material sciences that concerns application, synthesis, design, and characterization of polymers or small organic molecules which show wanted properties electronically like conductivity. Unlike semiconductors and inorganic conventional conductors, materials of organic electronics have been constructed from (carbon-based) organic polymers or small molecules organic by using strategies synthetically being developed in contexts of polymer and organic chemistry. One advantage of organic electronics is low cost of theirs in comparison to traditional and old inorganic electronics.
Organic Electronic Devices: Organic Solar Cells: When compared with inorganic conventional solar cells, there is a benefit of organic solar cells which is that it has low fabrication cost. Organic Solar Cells is device which uses organic electronics for converting light to electricity. Organic Solar Cells use organic semiconductor diodes and organic photovoltaic materials for converting light to electricity. There are 5 used commonly photovoltaic organic materials. Electrons in organic molecules are delocalized in delocalized “pi” orbital with corresponding “pi*” antibonding orbital. Energy difference in between “pi” orbital or (HOMO) highest occupied molecular orbital and “pi*” orbital or (LUMO) lowest unoccupied molecular orbital is known as band gap of photovoltaic organic materials. Band gap typically, lies in ranges of 1eV to 4eV. Band gap differences of photovoltaic organic materials lead to various chemical structures forming organic solar cells. Various forms of solar cells include single layered organic photovoltaic cells, heterojunction photovoltaic cells and bilayered organic photovoltaic cells. All, however, 3 of these solar cells types shares approaches sandwiching organic electronic layers in between 2 metallic conductors like indium tin oxide.
Organic Field-Effect Transistors: It consists of 3 important components namely gate, drain and source. Field-Effect Transistors (FET) generally, have 2 plates. This is source in contacts with drain and gate respectively. This works as conducting channel. Electrons move from source to drain. Gate serves controlling electron movement from source to drain. FETs different types have been designed on basis of carrier properties. (TFT) Thin film transistor amongst them is easy one whilst fabricating. In thin film transistor drain and source are directly made by deposition of thin semiconductor layer followed by thin insulator film in between metal gate and semiconductor contact. Such thin film is created by thermal evaporation either or spinning coating simply. In TFT devices, there not at all are carrier movements in between drain and source. After application of positive charges, an electron accumulation on interfaces causes semiconductor bending. It lowers ultimately conduction band with respect to Fermi level of semiconductor. Highly conductive channel is formed at interface.
Methods of fabrication: There are differences important in between processing of semiconducting polymers and small molecule organic semiconductors. Semiconductors small molecule is often quite insoluble. They need typically deposition by means of vacuum sublimation. Whilst thin films usually are soluble polymers conjugated. Device based on polymers conductive are prepared by solution’s processing ways. 2 solution processing and vacuum based ways produce polycrystalline and amorphous films with variable disorder degrees. Coating “wet” techniques need polymers dissolving in volatile solvents, being deposited and filtered to substrates. Examples commonly are solvent based techniques of coating that includes screen printing, drop casting, inkjet printing, and doctor blading and spin coating. Spin coating is technique used widely for thin film small area production.
It results in high degrees of loss of materials. Doctor blade techniques result in less loss of material. It was developed primarily for thin film large area production. Vacuum based deposition thermally of small molecules need molecules evaporation from hot sources. Molecules then are transported by means of vacuum to substrates. Condensing molecules processes on surface of substrates result in formation of thin film.