Solid state amplified spontaneous emission in some spiro-type molecules: A new concept for the design of solid state lasing molecules

Here are presented initial results on spectral narrowing in submicron thick neat films, of 2,2′,7,7′-tetraphenyl-9,9′-spirobifluorene (spiro-quarterphenyl) and 2,2′,7,7′-tetrakis(biphenyl-4-yl)-9,9-spirobiflourene (spiro-sexiphenyl). The luminescence effects reported here are common to several other molecules which belong the class of molecules known as the spiro-type molecules. The Amplified Spontaneous Emission (ASE) is evidenced by a dramatic collapse of the line width, when pumped with sufficient energy, down to 2.2 and 2.9 nm for spiro-quarterphenyl and spiro-sexiphenyl, respectively. These molecules have the ability to form stable, amorphous films with glass transition temperatures at around 200 °C. Thus, these molucules are suitable candidates as the active material in molecular solid state injection lasers.