InGaN/GaN ultraviolet LED with a graphene/AZO transparent current spreading layer

Liu, Lin; Ou, Yiyu; Zhu, Xiaolong; Stamate, Eugen; Wu, Kaiyu; Meng, Liang; Liu, Zhiqiang; Yi, Xiaoyan; Herstrøm, Berit; Boisen, Anja; Jensen, Flemming; Ou, Haiyan

doi:10.1364/ome.8.001818

Cited by 8 publications

(6 citation statements)

References 43 publications

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“…Countless efforts have been conducted to specify the desired wavelength and the PL intensity of DUV-LED [14,15]. Most works focus on the types of material used to generate the UV spectrum, such as the near UVLED, Indium Gallium Nitride (InGaN) [16][17][18], and the DUV-LED Aluminium Gallium Nitride (AlGaN) [11,[19][20][21][22][23][24]. The width of the quantum well also plays a role in deciding the emitted UV-spectrum [25].…”

Section: Introductionmentioning

confidence: 99%

High photoluminescence intensity of heterostructure AlGaN-based DUV-LED through uniform carrier distribution

Aman¹,

Fajri²,

Noorden³

et al. 2022

Phys. Scr.

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We report a numerical analysis of the variation of Aluminium (Al) composition in Al Gallium Nitride (AlGaN)-based Deep-Ultraviolet Light-Emitting Diode (DUV-LED) and its effects on the carrier concentration, radiative recombination, and photoluminescence (PL). Three different structures with different Al compositions are compared and analyzed. The radiative recombination of the DUV-LED is less efficient due to the imbalance of carrier distribution. The findings show that the uniform electrons and holes distribution significantly improve the radiative recombination for structure with a thin step-shaped quantum well (QW). The simulated structure emits a wavelength of 302.874 nm, categorized in the ultraviolet-B (UV-B) spectrum. Our results imply that carrier uniformity in QW is required to enhance the light intensity of DUV-LED. Remarkably, the uniformity enhances the PL intensity drastically, at least six times higher than the first structure and twice higher than the second structure.

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Section: Introductionmentioning

confidence: 99%

High photoluminescence intensity of heterostructure AlGaN-based DUV-LED through uniform carrier distribution

Aman¹,

Fajri²,

Noorden³

et al. 2022

Phys. Scr.

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“…The reason might be that the RTA treatment eradicates the photoresist residuals [ 73 ], enhances the adhesion between layers [ 74 ] and lowers the Schottky barrier height (SBH) by formation of a metal-Ga solid solution at the interface [ 73 ]. This improvement could also be revealed by the reduced

from 6.2 V (graphene-only TCSL) to 4.8 V (3 nm Ni/graphene hybrid TCSL) [ 32 ] and the enhanced EL intensity [ 34 , 75 ].…”

Section: Graphene As Tcsl In Gan-based Ledsmentioning

confidence: 99%

Graphene as a Transparent Conductive Electrode in GaN-Based LEDs

et al. 2022

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Graphene combines high conductivity (sheet resistance down to a few hundred Ω/sq and even less) with high transparency (>90%) and thus exhibits a huge application potential as a transparent conductive electrode in gallium nitride (GaN)-based light-emitting diodes (LEDs), being an economical alternative to common indium-based solutions. Here, we present an overview of the state-of-the-art graphene-based transparent conductive electrodes in GaN-based LEDs. The focus is placed on the manufacturing progress and the resulting properties of the fabricated devices. Transferred as well as directly grown graphene layers are considered. We discuss the impact of graphene-based transparent conductive electrodes on current spreading and contact resistance, and reveal future challenges and perspectives on the use of graphene in GaN-based LEDs.

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“…Despite the fact that transparent conducting oxides (TCOs) such as indium tin oxide and aluminum-doped zinc oxide are widely used in blue LEDs for effective current spreading [15][16][17][18][19], there is no suitable TCO available in wavelength of deep UV so far. The lacking of TCO poses a fundamental bottleneck for the hole injection in AlGaN-based DUV-LED.…”

Section: Introductionmentioning

confidence: 99%

Current crowding in deep ultraviolet light-emitting diodes with fish-bone shaped p-electrode by microscopic emission investigation

Chen

et al. 2023

Semicond. Sci. Technol.

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Current crowding is the main bottleneck preventing the prosperity of AlGaN-based deep-ultraviolet light-emitting-diodes (DUV-LEDs) considering the low electrical conductivity of p-type contact layer. A deeper understanding of the current distribution in p-AlGaN is critical, which enables the rational design of advanced device architectures. In this work, a fish-bone-shaped p-type electrode was deposited on top of a 280 nm AlGaN DUV-LED for investigation of localized emissions. A significantly raised junction temperature was identified, causing efficiency droop in DUV-LEDs under relatively low injection current with fish-bone-shaped p-type electrodes. High junction temperature is attributed to the significantly high localized current density which is confirmed by the spatial-resolved electroluminescence (EL) spectra and theoretical simulation. The crowding current level beneath the p-electrodes is estimated to be several times higher than that in between the electrodes.

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InGaN/GaN ultraviolet LED with a graphene/AZO transparent current spreading layer

Cited by 8 publications

References 43 publications

High photoluminescence intensity of heterostructure AlGaN-based DUV-LED through uniform carrier distribution

High photoluminescence intensity of heterostructure AlGaN-based DUV-LED through uniform carrier distribution

Graphene as a Transparent Conductive Electrode in GaN-Based LEDs

Current crowding in deep ultraviolet light-emitting diodes with fish-bone shaped p-electrode by microscopic emission investigation

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