Charged Polariton Luminescence from an Organic Semiconductor Microcavity

Strong coupling light to polaron optical transitions in an organic semiconductor microcavity leads to an unusual class of polariton that possesses a net charge. This species may offer a range of technologically useful optoelectronic properties but has thus far only been observed in passive reflectivity measurements. Here, we report room-temperature photoluminescence from both upper and lower branch polaron polariton states that originate from hole excitations in a p-doped 4,4′-cyclohexylidenebis[N,N-bis(4-methylphenyl)benzenamine] (TAPC) microcavity. Our observations under nonresonant excitation are in good agreement with classical dipole emission modeling, which suggests that polariton states in this system are populated radiatively via fluorescence from the polaron excited state reservoir. These results constitute one of the first observations of polaron luminescence from an organic semiconductor thin film and are an important prerequisite for realizing a charged polariton condensate.