Microdisk lasers and field effect transistors of thiophene/phenylene co-oligomers by using high temperature deposition method

Microdisk lasers of the organic semiconductor material thiophene/phenylene co-oligomer (TPCO) have been fabricated on Si/SiO2 substrates. Quality of the organic films is improved by using the high temperature deposition method, and microcavities without grain boundaries and cracks are obtained. As a result, microdisks with 1 μm diameter are fabricated successfully. Comparing with the bulk film part, the lasing threshold is reduced to 2% of the annealed bulk film parts. A part of the reduction comes from the improved quality of crystal films and another part of the reduction from the small disk size. To our knowledge, this is the smallest microdisk cavity made from organic crystals ever reported. The TPCO crystal films fabricated by using the high temperature deposition method also show the good performance of p-channel field effect transistor operation.