| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 103 === In this thesis, InGaN-based light emitting diodes (LED) with embedded conductive nanoporous-GaN/undoped-GaN (NP-GaN/u-GaN) distributed Bragg reflectors (DBR) have been demonstrated. The nanoporous GaN DBR structures were fabricated through a pulse 355nm laser scribing process and an electrochemical etching (EC) process. Si-heavy doped GaN:Si layers (n+-GaN) in the 8-period n+-GaN/u-GaN stack structure were transformed into a low refractive index and a conductive nanoporous GaN structure.
8-period DBR structure consisted of a quarter-wavelength (1/4λ) NP-GaN layer and a five-quarter-wavelength (3/4λ) u-GaN layer. The center wavelength, peak reflectivity, and stop-band width of the nanoporous GaN DBR structure were measured at 417 nm, 96.3%, and 25.6 nm, respectively. The reflectivity of active layer was 92.6% at 410 nm. The region of EC-LED by EC etching process had high EL intensity that corresponded with beam profile. The resonance cavity modes of the PL spectra were observed by 266 nm pulse laser source in the EC-LED structure with the nanoporous DBR structure. InGaN LED structure with embedded NP-GaN/u-GaN DBR structure had been fabricated that have potential for the high efficiency and the resonant-cavity optoelectronic device applications.
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