what is organic photovoltaic materials?

organic photovoltaic materials is a specialized semiconductor diode that converts visible light into direct current (DC) electricity. Some photovoltaic cells can convert the infrared (IR) or ultraviolet (UV) radiation in DC.Zajedničko feature of both small molecules and polymers (Figure 1) is used in photovoltaic systems is that they all have great sustav.Konjugirani conjugated system is formed in which carbon atoms covalently links with alternating single and double bonds, in other words to the chemical reactions of hydrocarbons. These electrons hydrocarbons PZ orbitals delocalize and form delocalized π orbital relationship with the π * antibonding π orbitals orbitalne.Delokalizirana the highest occupied molecular orbital (homo), and π * orbital of the lowest unoccupied molecular orbital (LUMO). Separation between Homo and the LUMO band is considered organic electronic materijala.Pojas is usually in the range of 1-4 eV.

  When these materials absorb a photon, an excited state is created and limited to molecules or polymers lanca.Pobuđeno state area can be considered as an electron hole pair is connected by electrostatic interactions, ie excitons. In photovoltaic cells, excitons are broken up into free electrons hole pairs polja.Na effective force fields are set by creating a heterojunction between two different materials. Effective field excitons that break down causing an electron falls from conducting band absorber band for the implementation of the acceptor molecule. It is essential that the acceptor material conduction band edge, which is lower than the absorber material
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