Dependence of adhesion strength between GaN LEDs and sapphire substrate on power density of UV laser irradiation

Park, Junsu; Sin, Young-Gwan; Kim, Jae Hyun; Kim, Jaegu

doi:10.1016/j.apsusc.2016.05.078

Cited by 28 publications

(11 citation statements)

References 22 publications

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“…Plenty of researches have been done to choose appropriate laser processing parameters to avoid the occurrence of defects which affects the electronic/optical properties of the released GaN . It has been found that the laser scanning speed could alter the structural quality of the GaN films .…”

Section: Laser Lift‐off Processmentioning

confidence: 99%

“…It has been found that the laser scanning speed could alter the structural quality of the GaN films . The adhesion strength between GaN and sapphire substrate is closely related to the energy density of UV laser irradiation . Typically, excessive relieved stress and vaporization pressure of nitrogen formed by the decomposition of GaN is the most possible explanation of the generated stresses and cracking in GaN film .…”

Section: Laser Lift‐off Processmentioning

confidence: 99%

See 1 more Smart Citation

Laser Transfer, Printing, and Assembly Techniques for Flexible Electronics

Bian

Zhou

Wan

et al. 2019

Adv Elect Materials

112

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materials and enable innovative applications that are hard to achieve with current microelectronics. Examples vary from biointegrated devices for clinical diagnosis and treatment, [11][12][13] to electronic skin (E-Skin), [14][15][16] energy harvesting/storage devices, [17][18][19][20][21] and sweat sensor, [22,23] to flexible display, [24,25] and to RFID tags, [26,27] etc.Two main kinds of microfabrication processes have been developed for flexible electronics, including the solutionprocessable methods and vacuum-based methods (lithographic patterning and undercut etching). [28] The former is naturally compatible with flexible substrates and can deposit and pattern functional materials in one single step. [29][30][31] They have fabricated various printed electronics with increasing performance, such as conductive metal wires, [32][33][34] thin film transistors (TFTs), [35][36][37] and piezoelectric devices. [38][39][40][41] However, the electronic performance is still limited by the properties of solution-processable functional materials and low resolution of printing techniques, with respect to standard microfabrication process. [42] On the other side, vacuum-based microfabrication techniques provide wellestablished routes to realize high-performance electronics, but generally incompatible with large-area, flexible (polymeric substrates). Ideally, high performance flexible electronics systems are usually fabricated by built-up process that begins with independent fabrication of high-modulus, fragile, chip-scale elements (e.g., IC chips, MEMS, sensors, and power sources) or flexible devices (e.g., flexible sensor, flexible display, and TFT array) on donor wafers, followed by being transferred onto flexible/stretchable substrates.The above manufacturing routes of flexible electronics can be concluded as the transfer of the materials, components, and devices from original fabricated/prepared substrates to flexible ones. The most significant built-in challenge in transferring is to control of interface status to accommodate to the disparate nature of the transferred objects from donor wafer/substrate. Distinctive assembly techniques based on stress-induced interface fracture have been invented to be adaptive to the diversity of material properties and geometric sizes that lead to tremendous differences in mechanical properties. For those conventional rigid electronic components like IC chips, they are transferred by standard single-ejector needle pick-and-place It is challenging to manufacture large-area, ultrathin, flexible/stretchable electronics on an industrial scale. Recent ground-breaking advances in the manufacture of flexible electronics are based on powerful laser processes. Laser irradiation at an internally absorbing interface through a transparent substrate will bring various physical changes and chemical reactions at the interface, accompanied by distinct phenomena. Numerous techniques derived from these phenomena with the unique ability to fabricate materials, structures, and devices on flexible subst...

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Section: Laser Lift‐off Processmentioning

confidence: 99%

Section: Laser Lift‐off Processmentioning

confidence: 99%

Laser Transfer, Printing, and Assembly Techniques for Flexible Electronics

Bian

Zhou

Wan

et al. 2019

Adv Elect Materials

112

View full text Add to dashboard Cite

show abstract

“…However, the efficiency of the LEDs remains below 100%. 1,2 The main reason to this issue is related to the large mismatch of lattice structure between sapphire and GaN materials, that results in high threading dislocations. 3 If such dislocations propagate into multi-quantum wells (MQWs) active region of the LEDs, they would act as non-radiative recombination centres.…”

Section: Introductionmentioning

confidence: 99%

Growth of Bulk Gallium Nitride Single Crystal by Sodium Flux Method: A Brief Review

Sin¹,

Ibrahim²,

Zainal³

2019

JPS

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Growing interest in homoepitaxial growth of nitride-based devices has driven considerable efforts towards producing bulk gallium nitride single crystal as a substrate for the devices. Therefore, the process of producing the bulk gallium nitride crystal substrate should be simple and yet cost-effective to reduce the production cost of the devices. To date, several methods of growing bulk gallium nitride crystal have been proposed. Sodium flux method is one of the most promising ways since it requires a moderate growth temperature and growth pressure, as well as being simple and costeffective. This paper will briefly review the progress made to advance the growth of bulk gallium nitride single crystal by sodium flux method, including discussing challenges and proposing possible improvements in future.

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“…In general, the commercial approach for w‐LEDs fabrication is combining a blue GaInN chip with a yellow YAG:Ce phosphor . However, the lack of red emission in white light results in a low color rendering index (CRI) and high correlated color temperature (CCT), and limits the further application of w‐LEDs . For solving this problem, the w‐LEDs can be composed of tricolor (red, blue, and green) phosphors that are excited by UV chip.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and luminescence properties of single‐component Ca₅(PO₄)₃F:Dy³⁺, Eu³⁺ white‐emitting phosphors

Zhang

Qin

et al. 2018

J Am Ceram Soc

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A series of Ca5(PO4)3F:Dy3+, Eu3+ phosphors was synthesized by a solid‐state reaction method. The XRD results show that all as‐prepared Ca5(PO4)3F:Dy3+, Eu3+ samples match well with the standard Ca5(PO4)3F structure and the doped Dy3+ and Eu3+ ions have no effect on the crystal structure. Under near‐ultraviolet excitation, Dy3+ doped Ca5(PO4)3F phosphor shows blue (486 nm) and yellow (579 nm) emissions, which correspond to 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively. Eu3+ co‐doped Ca5(PO4)3F:Dy3+ phosphor shows the additional red emission of Eu3+ at 631 nm, and an improved color rendering index. The chromaticity coordinates of Ca5(PO4)3F:Dy3+, Eu3+ phosphors also indicate the excellent warm white emission characteristics and low correlated color temperature. Overall, these results suggest that the Ca5(PO4)3F:Dy3+, Eu3+ phosphors have potential applications in warm white light‐emitting diodes as single‐component phosphor.

show abstract

Dependence of adhesion strength between GaN LEDs and sapphire substrate on power density of UV laser irradiation

Cited by 28 publications

References 22 publications

Laser Transfer, Printing, and Assembly Techniques for Flexible Electronics

Laser Transfer, Printing, and Assembly Techniques for Flexible Electronics

Growth of Bulk Gallium Nitride Single Crystal by Sodium Flux Method: A Brief Review

Synthesis and luminescence properties of single‐component Ca₅(PO₄)₃F:Dy³⁺, Eu³⁺ white‐emitting phosphors

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Dependence of adhesion strength between GaN LEDs and sapphire substrate on power density of UV laser irradiation

Cited by 28 publications

References 22 publications

Laser Transfer, Printing, and Assembly Techniques for Flexible Electronics

Laser Transfer, Printing, and Assembly Techniques for Flexible Electronics

Growth of Bulk Gallium Nitride Single Crystal by Sodium Flux Method: A Brief Review

Synthesis and luminescence properties of single‐component Ca5(PO4)3F:Dy3+, Eu3+ white‐emitting phosphors

Contact Info

Product

Resources

About

Synthesis and luminescence properties of single‐component Ca₅(PO₄)₃F:Dy³⁺, Eu³⁺ white‐emitting phosphors