On the basis of optimizing the process conditions of molecular beam epitaxy (MBE), the GaN thin film with high quality was prepared by using sapphire (0001) vicinal substrate. HP-5000 type transistor characteristic tester was employed to measure the dark state current-voltage (I-V) characteristics of the GaN thin film metal–semiconductor–metal (MSM) structure grown on adjacent crystal surface by MBE. It was found that this kind of MSM structures had shown a rectifying contact characteristic. The dynamic photoconductive characteristics of the GaN based MSM structure and the transient photocurrent characteristics of the reverse bias diode were simulated by using PSPICE. The results showed that the transient photocurrent response time was in nanosecond level, under the condition of pulse width 800ps, wavelength 355nm light excitation.
The surface morphology and structural properties of Fe doped GaN alloy samples were analyzed by SPM9700 atomic force microscope and X LabXRD-6100 ray diffraction. The equivalent diameter of crystallite size was calculated to be 18nm according to the XRD data. The photoluminescence spectra of the samples were measured by 325nm continuous laser excitation at room temperature. The peaks position of the photoluminescence spectra of the samples was located at 450nm, 585nm and 665nm respectively. The waveguide effect was observed and analyzed. The peak wavelength of the waveguide is mainly in the 543nm. The results suggested significantly for further improvement of the performance of GaN based electronic devices and optoelectronic devices.
The time-resolved photoluminescence spectra were investigated on the basis of transmission, reflection and
photoluminescence studies of the InGaN single quantum well structure grown by metalorganic chemical vapor deposition.
It was found that the temporal responses of photoluminescence decay exhibited exponential function. The multi-peak
structure of the photoluminescence spectra was attributed to the Fabry-Perot interference effect in the GaN/InGaN/GaN