| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 104 === In this thesis, we designed to fabrication the AlGaN-based light emitting diodes (LED) at 360 nm with embedded the nanoporous structure that the experiments had divided into two parts. In the first part, the AlGaN distributed bragg reflector (DBR) with different aluminum contents were designed and fabricated. The porous size and reflectivity of the nanoporous AlGaN reflectors were analyzed by varying the Al content from 6%, 8.5%, 14%, to 17% in AlGaN DBR samples. The crack surfaces of the AlGaN reflectors were caused by the lattice mismatch that will not influence the electrochemical etching process. High light reflectivity, large refractive index different, and wide stopband width were observed in the porous AlGaN DBR structure with 8.5% Al content. The AlGaN-based UV-LED with 8.5% nanoporous AlGaN DBR structure were designed to analyzed the optical properties of the UV-LED structures.
In the second part, a 361 nm UV-LED with embedded the twelve pairs of undoped / noporous AlGaN DBR were designed and fabricated. The center wavelength, peak reflectivity, and stop-band width of the UC-LED with a nanoporous AlGaN DBR structure were measured at 380 nm, 77.2%, and 24 nm, respectively. High light reflectance and high light extraction efficiency were observed in the treated DBR structure with nanoporous AlGaN-based DBR structure.
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