scholarly journals A Schottky-Type Metal-Semiconductor-Metal Al0.24Ga0.76N UV Sensor Prepared by Using Selective Annealing

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4243
Author(s):  
Byeong-Jun Park ◽  
Jeong-Hoon Seol ◽  
Sung-Ho Hahm
Keyword(s):  
Current Density ◽  
Aluminum Gallium Nitride ◽  
Photoelectron Spectroscopy ◽  
Dark Current ◽  
Dark Current Density ◽  
Transmission Electron Microscopy Analysis ◽  
Ohmic Behavior ◽  
Metal Semiconductor Metal ◽  
Electron Microscopy Analysis ◽  
And Performance

Asymmetric metal-semiconductor-metal (MSM) aluminum gallium nitride (AlGaN) UV sensors with 24% Al were fabricated using a selective annealing technique that dramatically reduced the dark current density and improved the ohmic behavior and performance compared to a non-annealed sensor. Its dark current density at a bias of −2.0 V and UV-to-visible rejection ratio (UVRR) at a bias of −7.0 V were 8.5 × 10−10 A/cm2 and 672, respectively, which are significant improvements over a non-annealed sensor with a dark current density of 1.3 × 10−7 A/cm2 and UVRR of 84, respectively. The results of a transmission electron microscopy analysis demonstrate that the annealing process caused interdiffusion between the metal layers; the contact behavior between Ti/Al/Ni/Au and AlGaN changed from rectifying to ohmic behavior. The findings from an X-ray photoelectron spectroscopy analysis revealed that the O 1s binding energy peak intensity associated with Ga oxide, which causes current leakage from the AlGaN surface, decreased from around 846 to 598 counts/s after selective annealing.

Short-wave infrared detector with double barrier structure and low dark current density

2016 ◽  
Vol 14 (2) ◽  
pp. 022501-22505
Author(s):  
Yu Dong Yu Dong ◽  
Guanglong Wang Guanglong Wang ◽  
Haiqiao Ni Haiqiao Ni ◽  
Kangming Pei Kangming Pei ◽  
Zhongtao Qiao Zhongtao Qiao ◽  
...  
Keyword(s):  
Current Density ◽  
Dark Current ◽  
Infrared Detector ◽  
Short Wave ◽  
Barrier Structure ◽  
Dark Current Density ◽  
Double Barrier ◽  
Short Wave Infrared ◽  
Double Barrier Structure

scholarly journals Structural, Optical and Electrical Characterizations of Midwave Infrared Ga-Free Type-II InAs/InAsSb Superlattice Barrier Photodetector

Photonics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 76
Author(s):  
U. Zavala-Moran ◽  
M. Bouschet ◽  
J. Perez ◽  
R. Alchaar ◽  
S. Bernhardt ◽  
...  
Keyword(s):  
Current Density ◽  
Dark Current ◽  
Spectral Response ◽  
Minority Carrier Lifetime ◽  
Peak Position ◽  
Type Ii ◽  
Dark Current Density ◽  
Time Resolved ◽  
Midwave Infrared ◽  
Electrical Characterizations

In this paper, a full set of structural, optical and electrical characterizations performed on midwave infrared barrier detectors based on a Ga-free InAs/InAsSb type-II superlattice, grown by molecular beam epitaxy (MBE) on a GaSb substrate, are reported and analyzed. a Minority carrier lifetime value equal to 1 µs at 80 K, carried out on dedicated structure showing photoluminescence peak position at 4.9 µm, is extracted from a time resolved photoluminescence measurement. Dark current density as low as 3.2 × 10−5 A/cm2 at 150 K is reported on the corresponding device exhibiting a 50% cut-off wavelength around 5 µm. A performance analysis through normalized spectral response and dark current density-voltage characteristics was performed to determine both the operating bias and the different dark current regimes.

scholarly journals Demonstration of Planar Type-II Superlattice-Based Photodetectors Using Silicon Ion-Implantation

Photonics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 68
Author(s):  
Arash Dehzangi ◽  
Donghai Wu ◽  
Ryan McClintock ◽  
Jiakai Li ◽  
Alexander Jaud ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Quantum Efficiency ◽  
Current Density ◽  
Dark Current ◽  
Infrared Photodetectors ◽  
Type Ii ◽  
Dark Current Density ◽  
Applied Bias ◽  
Type Ii Superlattice ◽  
Specific Detectivity

In this letter, we report the demonstration of a pBn planar mid-wavelength infrared photodetectors based on type-II InAs/InAs1−xSbx superlattices, using silicon ion-implantation to isolate the devices. At 77 K the photodetectors exhibited peak responsivity of 0.76 A/W at 3.8 µm, corresponding to a quantum efficiency, without anti-reflection coating, of 21.5% under an applied bias of +40 mV with a 100% cut-off wavelength of 4.6 µm. With a dark current density of 5.21 × 10−6 A/cm2, under +40 mV applied bias and at 77 K, the photodetector exhibited a specific detectivity of 4.95 × 1011 cm·Hz1/2/W.

A Novel Surface Preparation and Post-Etch Removal Technique for InGaAs Sidewalls

1997 ◽  
Vol 477 ◽  
Author(s):  
S. A. Tabatabaei ◽  
G. A. Porkolab ◽  
S. Agarwala ◽  
F. G. Johnson ◽  
S. A. Merritt ◽  
...  
Keyword(s):  
Current Density ◽  
Dark Current ◽  
High Speed ◽  
Surface Preparation ◽  
Reverse Bias Voltage ◽  
Dark Current Density ◽  
Term Stability ◽  
Long Term Stability ◽  
Removal Technique

ABSTRACTThis paper describes in detail a surface preparation, and post-etch removal technique developed for InGaAs sidewalls. It illustrates the results demonstrating the effect of sidewall post-etch, surface preparation, and surface passivation on the performance of high speed InGaAs detectors. Dark current density for circular diodes with a diameter size varying between 10 and 100 μm was measured at a reverse bias voltage of −5 V. The effectiveness of various surface preparation techniques was studied by measuring the immediate improvement in dark current density, as well as its long-term stability. The benefits of this new technique compared to other techniques we have investigated include improved device characteristics, long-term stability, as well as a much less critical process to achieve optimum surface properties.

scholarly journals Direct Vapor-Phase Bromination of Multiwall Carbon Nanotubes

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Ilya Mazov ◽  
Dmitry Krasnikov ◽  
Andrey Stadnichenko ◽  
Vladimir Kuznetsov ◽  
Anatoly Romanenko ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Vapor Phase ◽  
Photoelectron Spectroscopy ◽  
Surface Defects ◽  
Simple Procedure ◽  
Multiwall Carbon Nanotubes ◽  
Average Diameter ◽  
Transmission Electron Microscopy Analysis ◽  
Electron Microscopy Analysis ◽  
Multiwall Carbon

We present the simple procedure of the vapor-phase bromination of multiwall carbon nanotubes (MWNTs) at moderate temperatures. MWNTs with average diameter9±3 nm were treated with Br2vapors at 250°C to produce Br-functionalized product. Transmission electron microscopy analysis was used to prove low damage of MWNT walls during bromination. X-ray photoelectron spectroscopy (XPS) and differential thermal analysis (DTA) were used to investigate chemical composition of the surface of initial and brominated nanotubes. The experimental results show that the structure of MWNTs is not affected by the bromination process and the total amount of Br-containing surface functions reaches 2.5 wt. %. Electrophysical properties of initial and brominated MWNTs were investigated showing decrease of conductivity for functionalized sample. Possible mechanism of the vapor-phase bromination via surface defects and oxygen-containing functional groups was proposed according to data obtained. Additional experiments with bromination of annealed low-defected MWNTs were performed giving Br content a low as 0.75 wt. % proving this hypothesis.

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