Enhancement of two-photon-excited fluorescence by distributed Bragg reflectors

Abstract Blend films of 4,4,4-tris[3methylphenyl(phenyl)amino]triphenylamine and tris-[3-(3-pyridyl)mesityl] borane were successfully prepared on gallium nitride wafer. Like other two-photon-absorbing (TPA) materials, the blend film has relatively low luminous efficiency. To improve luminous efficiency, the blend film was embedded on nanoporous(NP)-GaN distributed Bragg reflector (DBR) fabricated by electrochemical etching. By comparison, we found that the photoluminescence intensity of the blend film on the DBR is 2.5 times bigger than that of the film on as-grown GaN, which should be contributed to light interference enhancement in the blend film. The results indicate that NP-GaN DBRs are promising candidates for improving luminous efficiency of TPA materials.