| Summary: | 碩士 === 中原大學 === 物理學系 === 88 === Owing to the blue light emitter of materials GaN and
related III-V nitride semiconductors with the wurtzite crystal
structure and a wide direct energy band gap, which are most
appropriate for using in optical devices, especially in blue
and ultraviolet light-emitting diodes (LEDs) and laser diodes
(LDs). In this study, the samples take the Mg-doped GaN films
are grown on c-face sapphire substrate by Atmospheric
pressure metalorganic chemical vapor deposition (AP-MOCVD)
using trimethylgallium (TMGa), NH3 and bis-Cyclopentadienyl
Magnesium (Cp2Mg) as Ga, N and Mg source, respectively.
Carrier gas and shroud gas are hydrogen (H2). The Mg-doped
GaN films are employing various grown temperature tares, and
these films are characterized by the microscope, room
temperature photoluminescence (PL) spectroscopy and Hall-effect measurements. Optimum Mg acceptor activation annealing conditions are determined to the 725℃for 20 minutes in a
nitrogen ambient by PL measurement at room temperature. The
Mg-doped GaN films at 1120℃~112℃ are provided higher
carrier concentrations and better optical emission properties. The intensity of PL spectra is highest at 1120℃,and the PL peak around 4340(A) is observed at roomtemperature. The p-type GaN films with carrier concentrations and mobility about 7.78×1017(cm-3) and 3.75(cm2V-1sec-1), respectively, have been achieved at 1126℃.
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