Optical transitions in new trends organic materials
The PTCDA (3,4,9,10-perylenetetracarboxylic dianhydride and the NTCDA (1,4,5,8-naphtalenetetracarboxylic dianhydride) are aromatic, stable, planar and highly symmetric with unusual electrical properties. The PTCDA is an organic crystalline semiconductor of particular interest due to its excellent properties and electronic potential that are used in optoelectronic devices, and the NTCDA is monoclinic and its space group is similar to that of PTCDA. Recently, alternate layers of PTCDA and NTCDA were grown forming multiple structures of quantum wells showing a new class of materials with new optic lineal properties. Some have assured that their big utilities would be centered in the construction of diodes and possible guides of waves. We have carried out semi-empirical calculations of electronic structures and optic properties of PTCDA and NTCDA that show us that they are highly orderly polymeric structured semiconductors in a negative load state (charge state=?2).
ptcda ntcda organic semiconductors semiempirical methods