: Kyungtaek Min, Hyunho Jung, Yeonsang Park, Kyung-Sang Cho, Young-Geun Roh, Sung Woo Hwang and Heonsu Jeon

: Nanoscale 9(25), 8703-8709 (2017)

Phosphors, long-known color-converting photonic agents, are gaining increasing attention owing to the interest in white LEDs and related applications. Conventional material-based approaches to phosphor focus on obtaining desired absorption/emission wavelengths and/or improving quantum efficiency. Here, we report a novel approach for enhancing the performance of phosphors: structural modification of phosphors. We incorporated inorganic colloidal quantum dots (CQDs) into a lateral one-dimensional (1D) photonic crystal (PhC) thin-film structure, with its photonic band-edge (PBE) modes matching the energy of ‘excitation photons’ (rather than ‘emitted photons’, as in most other PBE application devices). At resonance, we observed approximately 4-fold enhancement of fluorescence over the reference bulk phosphor, which reflects an improved absorption of the excitation photons. This nano-structural engineering approach is a paradigm shift in the phosphor research area and may help to develop next-generation higher efficiency phosphors with novel characteristics.