Giant organic single-crystals of a thiophene/phenylene co-oligomer toward device applications

- We prepare giant organic thin single-crystals of 2,5-bis(4-biphenylyl)thiophene (BP1T). The largest crystal is 7.6 × 4.4 mm in size.
- We fabricate three field-effect transistor (FET) devices on a sole crystal at a time. These devices exhibit the normal device operation.
- The crystals show spectrally narrowed emission lines at higher excitation energies.
- The narrowed emission lines are accompanied by many fringes of concentric circles of various sizes.
- These observations strongly indicate that the emission is a coherent radiation.