Surface plasmon enhanced infrared photodetection
The research group of Prof. Dao Hua Zhang from Nanyang Technological University reviews the development of surface plasmon enhanced infrared photodetection. This review article introduces the physical background of surface plasmon polaritons and enhanced detection performance of different type of detectors which include heterojunction type, Schottky diode type, photoconductor type, heterostructure type and thermal type. By integrating a 2-dimensional metallic hole array with the InAsSb based n-i-p heterostructure, the room temperature detectivity can be enhanced to 8x109 Jones, and a single metallic hole array can enhance both near and mid-wave infrared detection with remarkable detectivities. These results give us hope for the uncooled mid-wave infrared detection systems. Finally, some prospects and challenges in surface plasmon enhanced photodetection are briefly discussed.
Schematic of the plasmonic 2DSHA-hetero n-i-p photodetector
The current research interests of Prof Zhang Dao Hua’group are III-V antimonide, optoelectronic devices, and optical metamaterials and applications. His team developed several kinds of infrared photodetectors, including InSbN based broadband photodetector, InAsSb phoconductive photodetector, InAsSb/GaSb heterostructure photodetectors and InAsSb based heterojunction photodetectors. Recently, the group invented a two-dimensional hole array enhanced InAsSb based middle infrared photodetector which can operate at room temperature with a record high detectivity of 8×109 Jones. They also developed a plasmonic enhanced dual-band heterostructure photodetector which can detect both near infrared and middle infrared with high performance at room temperature. Based on the high mobility and low plasma frequency of semiconductors, the group invented two terminal metal-semiconductor-metal millimetre- & terahertz-wave photodetectors which show a record-low noise equivalent power of <10-13 W Hz1/2 at room temperature. In optical material research, his team developed new technologies capable of large area and high density 2D and 3D metallic arrays with sub-10 nm wide lines and sub-15 nm diameter dots. With these technologies, split ring resonators (SRR) arrays with 60 nm SRRs are successfully fabricated and the magnetic resonances from infrared to near UV ranges are demonstrated. The group has also demonstrated refractive index sensors and biochemical sensors using 2-dimensional SRR arrays and enhanced emission in quantum dots using dimmer arrays.