Napthalimide End-Capped Diphenylacetylene: A Versatile Organic Semiconductor for Blue Light Emitting Diodes and Donor or Acceptor for Solar Cells
A novel compound 6,6'-(ethyne-1,2-diylbis(4,1-phenylene))bis(2-(2-butyloctyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione) (NAI-PVP-NAI) based on end capping groups 1,8-napthalimide and central building block diphenylacetylene was designed and synthesized by Suzuki coupling. The newly synthesized NAI-PVP-NAI compound is characterized using optical, thermal, and electrochemical techniques as well as ab initio modeling. This novel and unique compound exhibits strong blue emission in solid state and has been used successfully as an active light-emitting layer in organic light emitting diodes (OLEDs). Interestingly, the newly developed compound shows both electron donating and electron-accepting ability (in other words, ambipolar behavior) therefore, it can act as a donor or as an acceptor organic semiconductor. Indeed, upon evaluating this molecule in solution processable organic photovoltaics (OPV), it acts as a donor with PCBM acceptor as well as works as an acceptor with P3HT donor. Therefore, NAI-PVP-NAI is a versatile compound, which can play three roles as a blue light emitting layer in OLED and donor or acceptor in OPV.