Polysilane light-emitting diodes

This paper discusses the material factors which have led to a recent breakthrough in polysilane light-emitting diodes (LEDs) made from a diaryl polysilane, poly[bis(p-n-butylphenyl)silane] (PBPS), by comparing them with LEDs which employ a conventional polysilane, poly(methylphenylsilane). In contrast to LEDs based on conventional polysilanes in which a weak ultraviolet electroluminescence (EL) was detected either with a strong broad visible EL or only at low temperatures, room-temperature pure near-ultraviolet EL was observed with a quantum efficiency of 0.1% photons/electron with an electron injecting A1 electrode in PBPS-LEDs. We examined the spectroscopic, electronic and structural properties of PBPS, and ascribed to them the improvements observed in the EL characteristics. We also mention the possible future direction of polysilane LED research and other potential optoelectronics applications of polysilanes to the active medium of lasers.