Abstract
AbstractThe free exciton transition (near‐band‐edge emission, NBE) of ZnO at ≈388 nm can be strongly enhanced and even stimulated by an underlying photonic structure. 1D Photonic crystals, so‐called distributed Bragg reflectors, are utilized to suppress the deep‐level emission of ZnO (DLE, ≈500–530 nm). The reflector stacks are fabricated in a layer‐by‐layer procedure by wet‐chemical synthesis. They consist of low‐ε porous SiO2 layers and high‐ε TiO2 layers. Varying the thickness of the SiO2 layers allows tuning the optical bandgap in a wide range between ≈420 and 800 nm. A ZnO layer is deposited on top of the reflector stacks by sol–gel synthesis. The spontaneous photoluminescence (PL) emission of the ZnO film is modulated by the photonic structure. When the optical bandgap of the reflector is in resonance with the deep‐level emission of ZnO (DLE, ≈500–530 nm), then this defect‐related emission mode is suppressed. Strong NBE emission is observed even when the ZnO layer does not show any NBE emission (due to low crystallinity) in the absence of the photonic structure. With this cost‐efficient synthesis method, emitters for, e.g., luminescent gas sensors can be fabricated.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
