Fabrication and characterization of vertical microcavities containing a submicron particle film of 5,5′-di(4-biphenylyl)-2,2′-bithiophene

We show the first experimental evidence that submicron particles (diameter: approximately 400 nm) using 5,5'-di(4-biphenylyl)-2,2'-bithiophene (BP2T) prepared by a miniemulsion technique are effective active media for vertical microcavities. Selected area electron diffraction patterns confirm that crystalline BP2T submicron particles are obtained. In a distributed Bragg reflector-Au microcavity with BP2T submicron particles embedded in a poly(vinyl alcohol) (PVA) matrix (thickness: similar to 780 nm), gain-narrowed emissions are observed at the 0-3 emission band of BP2T above an excitation density of 107 mu J cm(-2). The light amplification of 0-3 photoluminescence band obtained in the present study demonstrates that the PVA film containing the BP2T submicron particles is useful as an active medium for microcavities. (C) 2020 The Japan Society of Applied Physics