Phosphor-Free InGaN White Light Emitting Diodes Using Flip-Chip Technology

Li, Ying-Chang; Chang, Liann‐Be; Chen, Hou-Jen; Yen, Chia-Yi; Pan, Ke-Wei; Huang, Bohr–Ran; Kuo, Wen-Yu; Chow, Lee; Zhou, Dan; Płaczek‐Popko, E.

doi:10.3390/ma10040432

Cited by 10 publications

(8 citation statements)

References 44 publications

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“…Over the past decade, phosphor-free white-or multicolour light emitting diodes (LEDs) based on InGaN/GaN have been attractive object, since they can overcome the drawbacks of common phosphor LEDs such as stokes energy conversion loss and reduced thermal stability of phosphor [11][12][13]. The growth of multiple InGaN quantum wells (QWs) or disks (QDs) with various In content in GaN NWs is currently prevalent in a significant number of publications [11,[14][15][16][17][18][19][20][21][22][23]. However, it is difficult to obtain uniform carrier injection into stacked QWs or QDs under electrical pumping [24,25].…”

Section: Introductionmentioning

confidence: 99%

Multi-colour light emission from InGaN nanowires monolithically grown on Si substrate by MBE

Gridchin¹,

Kotlyar²,

Reznik³

et al. 2021

Nanotechnology

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InGaN nanostructures are among the most promising candidates for visible solid-state lighting and renewable energy sources. To date, there is still a lack of information about the influence of the growth conditions on the physical properties of these nanostructures. Here, we extend the study of InGaN nanowires growth directly on Si substrates by plasma-assisted molecular beam epitaxy. The results of the study showed that under appropriate growth conditions a change in the growth temperature of just 10 °C leads to a significant change in the structural and optical properties of the nanowires. InGaN nanowires with the areas containing 4%–10% of In with increasing tendency towards the top are formed at the growth temperature of 665 °C, while at the growth temperatures range of 655 °C–660 °C the spontaneously core–shell NWs are typically presented. In the latter case, the In contents in the core and the shell are about an order of magnitude different (e.g. 35% and 4% for 655 °C, respectively). The photoluminescence study of the NWs demonstrates a shift in the spectra from blue to orange in accordance with an increase of In content. Based on these results, a novel approach to the monolithic growth of In x Ga1−x N NWs with multi-colour light emission on Si substrates by setting a temperature gradient over the substrate surface is proposed.

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Section: Introductionmentioning

confidence: 99%

Multi-colour light emission from InGaN nanowires monolithically grown on Si substrate by MBE

Gridchin¹,

Kotlyar²,

Reznik³

et al. 2021

Nanotechnology

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“…In our previous research, the flip-chip light-emitting diodes were mounted on transparent sapphire and glass, and both have shown a higher output luminous flux when compared to the traditional nontransparent mounted LEDs [ 14 ]. Unfortunately, as also shown in that study, the most cost-effective transparent submount GCB is not good thermal conductor, and heat accumulation severely affects its output performance as compared to those FCLEDs mounted on the high thermal conductivity sapphire substrate [ 15 , 16 , 17 , 31 , 32 ]. To solve this problem, an oil ECP technology was proposed in this work [ 6 ].…”

Section: Discussionmentioning

confidence: 89%

“…Furthermore, different types of packages are adopted to produce color-tunable LED modules [ 13 ]. Alternatively, flip chip (FC) technology is widely used [ 12 , 13 , 14 , 15 , 16 ]. However, most FCLED package submounts used today, whether PCB or MCPCB, are still not transparent, which theoretically decreases or even prevents the output light extraction.…”

Section: Introductionmentioning

confidence: 99%

RGB-Stack Light Emitting Diode Modules with Transparent Glass Circuit Board and Oil Encapsulation

Chang

Singh

et al. 2018

Materials

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The light emitting diode (LED) is widely used in modern solid-state lighting applications, and its output efficiency is closely related to the submounts’ material properties. Most submounts used today, such as low-power printed circuit boards (PCBs) or high-power metal core printed circuit boards (MCPCBs), are not transparent and seriously decrease the output light extraction. To meet the requirements of high light output and better color mixing, a three-dimensional (3-D) stacked flip-chip (FC) LED module is proposed and demonstrated. To realize light penetration and mixing, the mentioned 3-D vertically stacking RGB LEDs use transparent glass as FC package submounts called glass circuit boards (GCB). Light emitted from each GCB stacked LEDs passes through each other and thus exhibits good output efficiency and homogeneous light-mixing characteristics. In this work, the parasitic problem of heat accumulation, which caused by the poor thermal conductivity of GCB and leads to a serious decrease in output efficiency, is solved by a proposed transparent cooling oil encapsulation (OCP) method.

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“…Gallium nitride (GaN) with a wide-gap (~3.4 eV) is an excellent semiconductor material. Nowadays, it has been widely used in visible–UV light emitting devices (LEDs) [ 1 ], laser diodes (LDs), 5G communications, and high power/frequency transistors [ 2 , 3 ] because of its outstanding properties, such as high electron mobility and high breakdown voltage. Additionally, the high radiation tolerance [ 4 , 5 ] of GaN makes it a promising material for the application in satellites [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

Dynamics Studies of Nitrogen Interstitial in GaN from Ab Initio Calculations

Liu

Liao

et al. 2020

Materials

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Understanding the properties of defects is crucial to design higher performance semiconductor materials because they influence the electronic and optical properties significantly. Using ab initio calculations, the dynamics properties of nitrogen interstitial in GaN material, including the configuration, migration, and interaction with vacancy were systematically investigated in the present work. By introducing different sites of foreign nitrogen atom, the most stable configuration of nitrogen interstitial was calculated to show a threefold symmetry in each layer and different charge states were characterized, respectively. In the researches of migration, two migration paths, in-plane and out-of-plane, were considered. With regards to the in-plane migration, an intermediated rotation process was observed first time. Due to this rotation behavior, two different barriers were demonstrated to reveal that the migration is an anisotropic behavior. Additionally, charged nitrogen Frenkel pair was found to be a relatively stable defect complex and its well separation distance was about 3.9 Å. Part of our results are in good agreement with the experimental results, and our work provides underlying insights of the identification and dynamics of nitrogen interstitial in GaN material. This study of defects in GaN material is useful to establish a more complete theory and improve the performance of GaN-based devices.

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Phosphor-Free InGaN White Light Emitting Diodes Using Flip-Chip Technology

Cited by 10 publications

References 44 publications

Multi-colour light emission from InGaN nanowires monolithically grown on Si substrate by MBE

Multi-colour light emission from InGaN nanowires monolithically grown on Si substrate by MBE

RGB-Stack Light Emitting Diode Modules with Transparent Glass Circuit Board and Oil Encapsulation

Dynamics Studies of Nitrogen Interstitial in GaN from Ab Initio Calculations

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