The Effect of Indium Surfactant on the Optoelectronic and Structural Properties of MBE Grown Gallium Nitride

2000 ◽  
Vol 618 ◽  
Author(s):  
C.F. Zhu ◽  
W.K. Fong ◽  
B.H. Leung ◽  
C.C. Cheng ◽  
C. Surya ◽  
...  
Keyword(s):  
Gallium Nitride ◽  
Power Spectra ◽  
Low Frequency ◽  
Rf Plasma ◽  
Frequency Noise ◽  
Noise Power ◽  
Low Frequency Noise ◽  
X Ray Diffraction ◽  
X Ray ◽  
The One

ABSTRACTGallium nitride films were grown by rf-plasma assisted molecular beam epitaxy. A small indium flux was used as surfactant during the growth. The optical and electrical properties of the films grown with and without In surfactant were characterized by investigating the photoluminescence (PL), high resolution x-ray diffraction (HRXRD) and low-frequency noise power spectra. The sample grown in the presence of In surfactant showed a suppressed yellow luminescence (YL) compared to the one grown without In surfactant. Significant reduction in the full width at half maximum of the GaN (0002) x-ray diffraction peak, indicating a better film quality, was obtained when In surfactant was used during growth. Atomic force microscopy studies show that the root mean squared surface roughness for films grown with and without the In surfactant are 5.86 and 6.99 nm respectively indicating significant improvement in surface morphology. This is attributed to the enhanced 2-dimensional growth by In surfactant. A smaller Hooge parameter was obtained from the low-frequency noise measurement for the sample grown with In surfactant indicating that application of In surfactant led to significant reduction in the trap density of the material.

Nature of Low-Frequency Excess Noise in n-Type Gallium Nitride

2000 ◽  
Vol 622 ◽  
Author(s):  
C. F. Zhu ◽  
W. K. Fong ◽  
B. H. Leung ◽  
C. C. Cheng ◽  
C. Surya
Keyword(s):  
Flicker Noise ◽  
Power Spectra ◽  
Low Frequency ◽  
Excess Noise ◽  
Rf Plasma ◽  
Frequency Noise ◽  
Noise Power ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
X Ray

ABSTRACTLow-frequency noise is investigated in n-type GaN film grown by rf-plasma assisted molecular beam epitaxy. The temperature dependence of the voltage noise power spectra, SV(f), was examined from 400K to 80K in the frequency range between 30Hz and 100KHz, which can be modeled as the superposition of 1/f (flicker) noise G-R noise. At f > 500 Hz the noise is dominated by G-R noise with activation energies of 360meV and 65meV from the conduct band. The results clearly demonstrate the trap origin for both the 1/f noise and G-R noise. At the low-frequency range the fluctuation was dominated by 1/f noise. To determine the origin of the noise we considered both the bulk mobility fluctuation and the trap fluctuation models. Our experimental results showed that rapid thermal annealing (RTA) at 800°C resulted in over one order of magnitude decrease in the Hooge parameter. Annealing at temperatures in excess of 1000°C resulted in significant increase in the noise. Photoluminescence and x-ray diffraction measurements also showed that the crystallinity of the films improved with RTA at 800°C with an accompanying reduction in deep levels. Annealing at 900°C and 1000°C resulted in an increase in the FWHM of the x-ray diffraction indicative of thermal decomposition of the materials. The results are in excellent agreement with the trend of Hooge parameters as a function of annealing temperature, strongly indicating trap origin of the observed 1/f noise.

scholarly journals Measurements of Low Frequency Noise of Infrared Photo-Detectors with Transimpedance Detection System

2014 ◽  
Vol 21 (3) ◽  
pp. 461-472 ◽  
Author(s):  
Łukasz Ciura ◽  
Andrzej Kolek ◽  
Waldemar Gawron ◽  
Andrzej Kowalewski ◽  
Dariusz Stanaszek
Keyword(s):  
Dark Current ◽  
Detection System ◽  
Power Spectra ◽  
Low Frequency ◽  
Frequency Noise ◽  
Noise Power ◽  
Low Frequency Noise ◽  
Leakage Resistance ◽  
Noise Measurements ◽  
Hgcdte Detector

Abstract The paper presents the method and results of low-frequency noise measurements of modern mid-wavelength infrared photodetectors. A type-II InAs/GaSb superlattice based detector with nBn barrier architecture is compared with a high operating temperature (HOT) heterojunction HgCdTe detector. All experiments were made in the range 1 Hz - 10 kHz at various temperatures by using a transimpedance detection system, which is examined in detail. The power spectral density of the nBn’s dark current noise includes Lorentzians with different time constants while the HgCdTe photodiode has more uniform 1/f - shaped spectra. For small bias, the low-frequency noise power spectra of both devices were found to scale linearly with bias voltage squared and were connected with the fluctuations of the leakage resistance. Leakage resistance noise defines the lower noise limit of a photodetector. Other dark current components give raise to the increase of low-frequency noise above this limit. For the same voltage biasing devices, the absolute noise power densities at 1 Hz in nBn are 1 to 2 orders of magnitude lower than in a MCT HgCdTe detector. In spite of this, low-frequency performance of the HgCdTe detector at ~ 230K is still better than that of InAs/GaSb superlattice nBn detector.

Characterization Of G-R Noise In GaN Films Grown By RF-MBE On Intermediate-Temperature Buffer Layers

2001 ◽  
Vol 693 ◽  
Author(s):  
W.K. Fong ◽  
B.H. Leung ◽  
C.F. Zhu ◽  
Charles Surya
Keyword(s):  
Buffer Layer ◽  
Defect Density ◽  
Strong Dependence ◽  
Power Spectra ◽  
Low Frequency ◽  
Intermediate Temperature ◽  
Buffer Layers ◽  
Rf Plasma ◽  
Frequency Noise ◽  
Noise Power

AbstractWe report detailed investigations of generation-recombination (G-R) noise in GaN films grown by rf-plasma assisted molecular beam epitaxy on intermediate-temperature buffer layer (ITBL) in addition to conventional low-temperature buffer layer. To characterize the film quality affected by the use of ITBL, low-frequency noise measurements were performed. The voltage noise power spectra show a strong dependence on the thickness of the ITBL. A model has been presented to explain the observed G-R noise, which stipulates that the phenomenon arises from the thermally activated trapping and detrapping of carriers by traps. The process leads to the correlated fluctuations in both the carrier number and the coulombic scattering rate. Detailed numerical evaluation shows that number fluctuation dominates in our samples. The calculated trap densities show that the use of ITBL can effectively reduce defect density by over an order of magnitude.

X-ray bursts from 4U 1608-52 and the associated low frequency noise

1998 ◽  
Author(s):  
W. Yu ◽  
S. N. Zhang ◽  
B. A. Harmon ◽  
W. S. Paciesas ◽  
C. R. Robinson ◽  
...  
Keyword(s):  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
X Ray

Low-frequency noise in GaN thin films deposited by rf-plasma assisted molecular-beam epitaxy

2002 ◽  
Vol 91 (6) ◽  
pp. 3706-3710 ◽  
Author(s):  
B. H. Leung ◽  
W. K. Fong ◽  
C. F. Zhu ◽  
Charles Surya
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Low Frequency ◽  
Rf Plasma ◽  
Frequency Noise ◽  
Low Frequency Noise

Low-frequency noise in gallium nitride nanowire mechanical resonators

2012 ◽  
Vol 101 (23) ◽  
pp. 233115 ◽  
Author(s):  
Jason M. Gray ◽  
Kris A. Bertness ◽  
Norman A. Sanford ◽  
Charles T. Rogers
Keyword(s):  
Gallium Nitride ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Mechanical Resonators
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