Poly[(diphenylsilanediyl)ethynediyl]: Structure and optical and electroluminescent properties

Poly[(diphenylsilanediyl)ethynediyl] with a band‐gap energy of 5.2 eV is a wide‐band‐gap material with a photoluminescence maximum at a wavelength of 354 nm. It is suitable for the fabrication of ultraviolet electroluminescence diodes. The electroluminescence spectrum consists of a strong peak at 361 nm and a tail up to 570 nm. The external quantum emission efficiency at the main maximum, calculated in terms of emitted photons per transported electronic charge, is 0.01% (no sample optimization has been carried out). The electric characteristics are controlled by contact‐limited currents and double injection. The geometry of the neutral oligo[(diphenylsilanediyl)ethynediyl] molecule and its infrared spectra and the changes in the geometries and charge distributions during the formation of the positive and negative ions have been calculated by quantum chemical methods. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 208–214, 2007