A novel transparent ohmic contact of indium tin oxide to n-type GaN

Hwang, Jun–Dar; Yang, Gwo-Huei; Chang, Wen-Hao; Lin, Chien‐Chung; Chuang, Ricky W.; Chang, Shoou‐Jinn

doi:10.1016/j.mee.2004.09.002

Cited by 14 publications

(8 citation statements)

References 11 publications

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“…ITO is deposited by means of sputtering whose plasma process may damage the n-GaN, resulting in the generation of N vacancy and the effective removal of native oxide. This could improve the electrical property of n-type ohmic contact [22,23]. However, sputtering plasma could damage the electrical properties of p-GaN [24,25], resulting in an increase in the contact resistivity of p-type contacts and leading to high series resistance.…”

Section: Resultsmentioning

confidence: 99%

Improving Emission Uniformity of InGaN/GaN-Based Vertical LEDs by Using Reflective ITO/Ag n-Contact

et al. 2021

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We investigated the effect of Ti/Al and ITO/Ag n-type contacts on the emission uniformity and light output of different chip-size vertical-geometry light-emitting diodes (VLEDs) for vehicle headlamp application. The forward voltage of the Ti/Al-based reference VLEDs decreased from 3.38 to 3.20 V at 1500 mA with increasing chip size from (1280 × 1000 µm2) to (1700 × 1700 µm2), whereas that of the ITO/Ag-based samples changed from 3.37 to 3.15 V. Regardless of chip size, the ITO/Ag-based samples revealed higher light output power than the reference samples. For example, the ITO/Ag-based samples (chip size of 1700 × 1700 µm2) exhibited 3.4% higher light output power at 1500 mA than the reference samples. The ITO/Ag samples underwent less degradation in the Wall-plug efficiency (WPE) than the reference sample. For instance, the ITO/Ag-based samples (1700 × 1700 µm2) gave 4.8% higher WPE at 1500 mA than the reference samples. The ITO/Ag-based samples illustrated more uniform emission than the Ti/Al-based sample. Both the reference and ITO/Ag-based samples underwent no degradation when operated at 1500 mA for 1000 h.

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Section: Resultsmentioning

confidence: 99%

Improving Emission Uniformity of InGaN/GaN-Based Vertical LEDs by Using Reflective ITO/Ag n-Contact

et al. 2021

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“…There are several possible explanations as to why ITO ohmic contacts to p-Si 0.8 Ge 0.2 were produced: (a) the ITO sputtering helps to remove the native oxide layer [15] on the SiGe semiconductor, (b) the sputtering may induce point defects at the SiGe surface to act as acceptor-like trap centers [16]. In our studies, the ITO film is sputtered onto the Si 0.8 Ge 0.2 layer and the sputtering would damage the surface of Si 0.8 Ge 0.2 due to plasma bombardment, leading to more defect states being generated at the surface of the Si 0.8 Ge 0.2 layer.…”

Section: Resultsmentioning

confidence: 99%

Nonalloyed transparent ohmic contact of indium tin oxide to p-type Si0.8Ge0.2

et al. 2005

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“…In comparison to the Ohmic contact between ZnO and n-GaN, ITO usually has the Schottky contact with the n-GaN. This is attributed to the barrier heights of 0.63–0.95 eV between ITO and n-GaN 14 , 15 . Thus, ZnO-based materials could be more feasible as the ERNs than ITO.…”

Section: Introductionmentioning

confidence: 99%

“… Material Method Contact to n-GaN Resistivity (Ω-cm) Dilute magnetic doping Electron retarding Ref. ITO evaporation Schottky ~10 −4 w/o w/o 14 ITO sputtering & annealing Ohmic ~10 −4 w/o w/o 15 ZnO:Ga chemical vapor de position Ohmic ~10 −1 –10 −2 w/o w/o 16 ITO-ZnO co-sputtering Schottky 3.82 × 10 −4 w/o w/o 18 Ga 2 O 3 PLD Schottky >10 5 w/o w/o 19 Co-doped ZnO PLD Ohmic 4.3 × 10 −2 w w Our study …”

Section: Introductionmentioning

confidence: 99%

Slow Electron Making More Efficient Radiation Emission

Tien

2018

Sci Rep

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In conventional emitting devices, the mobility of electron is much higher than that of hole, which increases the non-recombination rate. To generate slow electrons, we demonstrate an electron retarding n-electrode (ERN) on the n-GaN layer of InGaN blue light emitting diode (LED), making more efficient radiation emission. Transparent conductive oxides are estimated to be more suitable for ERN materials. However, for ERN materials used in InGaN LEDs, three requirements should be satisfied, i.e., Ohmic contact to n-GaN, dilute magnetic doping, and good electrical conductivity. The pulsed-laser deposited cobalt-doped ZnO film prepared at 400 °C was chosen as the ERN. The electron retarding of 120-nm-thick ERN/n-GaN reached 19.9% compared to the n-GaN. The output powers (@350 mA) of LEDs with and without the ERN were 246.7 and 212.9 mW, while their wall-plug efficiencies were 18.2% and 15.1%, respectively. Moreover, owing to the efficient filling of electrons in the quantum wells by inserting the ERN, the bandgap of quantum wells was enlarged, inducing the blue-shift in the emission wavelength of LED. The slow electron generated from the ERN technique paves the way to solve the problem of large difference between electron and hole velocities and improve the optoelectronic performance of emitting devices.

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A novel transparent ohmic contact of indium tin oxide to n-type GaN

Cited by 14 publications

References 11 publications

Improving Emission Uniformity of InGaN/GaN-Based Vertical LEDs by Using Reflective ITO/Ag n-Contact

Improving Emission Uniformity of InGaN/GaN-Based Vertical LEDs by Using Reflective ITO/Ag n-Contact

Nonalloyed transparent ohmic contact of indium tin oxide to p-type Si0.8Ge0.2

Slow Electron Making More Efficient Radiation Emission

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