Microstructure Of Au/Ti Ohmic Contacts On n-GaN

1998 ◽  
Vol 4 (S2) ◽  
pp. 668-669
Author(s):  
R.-J. Liu ◽  
L. L. Smith ◽  
M. J. Kim ◽  
R. W. Carpenter ◽  
R. F. Davis
Keyword(s):  
Room Temperature ◽  
Ohmic Contacts ◽  
Light Emitting ◽  
Direct Band Gap ◽  
Au Film ◽  
Current Voltage ◽  
Direct Band ◽  
Si Doped ◽  
Emitting Lasers ◽  
A1n Buffer Layer

GaN is a semiconductor with a direct band-gap of 3.4 eV which has a potential application in optoelectronic devices such as UV-emitting lasers and blue light emitting diodes. Extensive efforts have been made to develop low-resistance, thermally stable and uniform ohmic contacts on GaN. In this study, n-GaN films (Si-doped) with an intermediate A1N buffer layer were grown on 6H-SiC substrates via MOVPE. The contacts were formed by depositing Ti and then Au films on GaN by e-beam evaporation at room temperature. Current-voltage measurements as a function of temperature showed that the ohmicity of the Au/Ti contact improved upon annealing, corresponding to changes in the microstructure of the contact interfaces involving a redistribution of nitrogen and gold.Fig. 1 shows the microstructure of the as-deposited Au/Ti/GaN films. The nanocrystalline Ti film was about 50 nm thick. Au film was polycrystalline, containing many growth twins. The thickness of Au film varied from 260 to 350 nm.

Room-temperature direct band-gap electroluminescence from germanium (111)-fin light-emitting diodes

2017 ◽  
Vol 56 (3) ◽  
pp. 032102 ◽  
Author(s):  
Kazuki Tani ◽  
Shin-ichi Saito ◽  
Katsuya Oda ◽  
Makoto Miura ◽  
Yuki Wakayama ◽  
...  
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Direct Band Gap ◽  
Direct Band

Ge and GeSn Light Emitters on Si

2015 ◽  
Vol 242 ◽  
pp. 353-360
Author(s):  
Michael Oehme ◽  
Martin Gollhofer ◽  
Konrad Kostecki ◽  
Roman Koerner ◽  
Stefan Bechler ◽  
...  
Keyword(s):  
Room Temperature ◽  
Light Emitting Diodes ◽  
Optical Feedback ◽  
Heteroepitaxial Growth ◽  
Light Emitters ◽  
Light Emitting ◽  
Direct Band Gap ◽  
Si Substrates ◽  
Direct Band ◽  
Clear Shift

The heteroepitaxial growth of GeSn and Ge crystals on Si substrates are investigated for Si-based photonic applications. Light Emitting Diodes with emission wavelengths from 2,100 to 1,550 nm could be demonstrated with active intrinsic GeSn light emitting layers between Ge barriers. A clear shift of the direct band gap toward the infrared beyond 2 μm is measured. Emission intensity is increased compared to Ge Light Emitting Diodes. Room temperature lasing from electrically pumped n-type doped Ge edge emitting devices are demonstrated. The edge emitter is formed by cleaving Si-Ge waveguide heterodiodes, providing optical feedback through a Fabry-Pérot resonator. The electroluminescence spectra of the devices showed optical bleaching and intensity gain for wavelengths between 1,660 nm and 1,700 nm.

Electrostatic Discharge Characteristics of InGaN/GaN Light-Emitting Diodes with Si-Doped Graded Superlattice

2015 ◽  
Vol 15 (10) ◽  
pp. 7733-7737 ◽  
Author(s):  
Kwanjae Lee ◽  
Cheul-Ro Lee ◽  
Jin Soo Kim ◽  
Jin Hong Lee ◽  
Kee Young Lim ◽  
...  
Keyword(s):  
Light Emission ◽  
Electrostatic Discharge ◽  
Light Emitting Diode ◽  
Emission Spectra ◽  
Small Variation ◽  
Injection Current ◽  
Light Emitting ◽  
Current Voltage ◽  
Gan Led ◽  
Si Doped

We report the influences of a Si-doped graded superlattice (SiGSL) on the electrostatic discharge (ESD) characteristics of an InGaN/GaN light-emitting diode (LED). For comparison, a conventional InGaN/GaN LED (C-LED) was also investigated. The luminous efficacy for the SiGSL-LED was 2.68 times stronger than that for the C-LED at the injection current of 20 mA. The resistances estimated from current–voltage (I–V) characteristic curves were 16.5 and 8.8 Ω for the C-LED and SiGSL-LED, respectively. After the ESD treatment at the voltages of 4000 and 6000 V, there was no significant change in the I–V curves for the SiGSL-LED. Also, there was small variation in the I–V characteristics for the SiGSL-LED at the ESD voltage of 8000 V. However, the I–V curves for the C-LED were drastically degraded with increasing ESD voltage. While the light emission was not observed at the injection current of 20 mA from the C-LED sample after the ESD treatment, the emission spectra for the SiGSL-LED sample were clearly measured with the output powers of 10.47, 9.66, and 7.27 mW for the ESD voltages of 4000, 6000, and 8000 V respectively.

GaN blue-light-emitting diode using room-temperature ohmic contacts

2001 ◽  
Author(s):  
Jong-Lam Lee ◽  
Ho W. Jang ◽  
Jung G. Kim ◽  
Changmin Jeon
Keyword(s):  
Blue Light ◽  
Room Temperature ◽  
Ohmic Contacts ◽  
Light Emitting Diode ◽  
Light Emitting

Direct band gap light emission and detection at room temperature in bulk germanium diodes with HfGe/Ge/TiN structure

2016 ◽  
Vol 602 ◽  
pp. 43-47 ◽  
Author(s):  
Dong Wang ◽  
Takayuki Maekura ◽  
Keisuke Yamamoto ◽  
Hiroshi Nakashima
Keyword(s):  
Band Gap ◽  
Room Temperature ◽  
Light Emission ◽  
Direct Band Gap ◽  
Direct Band

ELECTRICAL AND OPTICAL PROPERTIES OF OLED USING NEW EMISSIVE MATERIAL Al2Nq4

2006 ◽  
Vol 05 (06) ◽  
pp. 859-864
Author(s):  
KI-SUNG YANG ◽  
HO-SIK LEE ◽  
SEUNG-UN KIM ◽  
YOON-KI JANG ◽  
DOO-SEOK KIM ◽  
...  
Keyword(s):  
High Performance ◽  
Room Temperature ◽  
System Model ◽  
Flat Panel Display ◽  
Flat Panel ◽  
Electrical And Optical Properties ◽  
Light Emitting ◽  
Current Voltage ◽  
Analysis System ◽  
Green Photoluminescence

Since the first report of the light-emitting diodes based on Alq 3, many organic materials have been synthesized and extended efforts have been made to obtain high performance electroluminescent (EL) device. We synthesized new emissive material, 1, 4-dihydoxy-5, 8-naphtaquinone· Alq 3 complex( Al 2 Nq 4), and extended efforts have been made to obtain high-performance electroluminescent (EL) devices. Current–voltage (I–V) and luminance–voltage (L–V) characteristics were measured by Flat Panel Display Analysis System (Model 200-AT) at room temperature. The Al 2 Nq 4 shows green photoluminescence and electroluminescence spectra at about 510 nm, and ITO/Al 2 Nq 4/Cathode device shows typical rectifying characteristics.

Reabsorption effects on direct band gap emission from germanium light emitting diodes

2014 ◽  
Author(s):  
Yen-Yu Chen ◽  
Chia-Chun Yen ◽  
Yi-Hsin Nien ◽  
Wen-Wei Hsu ◽  
Qing-Qi Chen ◽  
...  
Keyword(s):  
Band Gap ◽  
Light Emitting Diodes ◽  
Light Emitting ◽  
Direct Band Gap ◽  
Direct Band
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