Optimising GaN light emitting structures on free-standing GaN substrates

优化独立式 GaN 衬底上的 GaN 发光结构

• 批准号: EP/E031625/1
• 负责人: Colin Humphreys
• 金额: $ 8.78万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2006
• 资助国家: 英国
• 起止时间: 2006 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE031625%2F1
• 关键词: Optimising; GaN; light; emitting; structures

Gallium nitride (GaN) is an amazing material that can emit brilliant light. GaN light emitting diodes (LEDs) first became available about ten years ago, and are already used in a wide range of applications, including interior lighting in cars, buses and planes; traffic lights, large full-colour displays and backlighting in mobile phones. GaN blue lasers are about to be sold for next-generation DVD players, in which the DVDs will contain more than five times the amount of music or pictures as existing DVDs. Looking to the future, GaN may make possible high-quality, high efficiency white lighting which will produce major energy savings. Another exciting development could be high-efficiency deep ultra-violet LEDs for water purification, particularly in the developing world.Unfortunately, we are currently unable to make the high-efficiency white lighting and deep-UV LEDs referred to above because there are some key scientific problems that remain to be solved. To successfully surmount these challenges requires a detailed understanding of the complex processes involved in the fabrication of the light emitting regions of the LED. These consist of thin layers of an alloy called InGaN, which are sandwiched between thicker layers of GaN to make structures called quantum wells. These quantum wells are 50,000 times thinner than a human hair. We must also understand the processes that limit light emission and optimise the electrical conductivity of the many other semiconductor layers in an LED.A major problem with GaN materials and devices is understanding the role of defects called dislocations. GaN devices are normally grown on sapphire or SiC. Because GaN has different atomic spacings from the atoms in sapphire or SiC, a very high number of dislocations are formed when GaN is grown on these materials. Recently free-standing bulk GaN with far fewer dislocations has become available in limited quantities. Because it is very difficult to grow, it is expensive. However, two producers of this material, Samsung Corning and Lumilog, have offered us some of this material free-of-charge, so that we can optimise the growth of GaN light-emitting structures: both blue and green. This is a wonderful opportunity to do this. As far as we are aware, no one in the world has grown green LEDs on GaN substrates. This research will not only produce blue and green LEDs, it will also help us to understand the role of dislocations in GaN LEDs.

氮化镓（GaN）是一种令人惊叹的材料，可以发出明亮的光。GaN发光二极管（LED）在大约10年前首次上市，并且已经被广泛应用，包括汽车、公共汽车和飞机的内部照明;交通信号灯、大型全彩显示器和移动的手机的背光。GaN蓝色激光器将用于下一代DVD播放器，其中DVD包含的音乐或图片数量将是现有DVD的五倍以上。展望未来，GaN可能使高质量、高效率的白色照明成为可能，这将节省大量能源。另一个令人兴奋的发展可能是用于水净化的高效深紫外LED，特别是在发展中国家。不幸的是，我们目前无法制造上面提到的高效白色照明和深紫外LED，因为还有一些关键的科学问题有待解决。为了成功克服这些挑战，需要详细了解LED发光区域制造中涉及的复杂工艺。这些由一种叫做InGaN的合金薄层组成，它夹在较厚的GaN层之间，形成称为量子威尔斯的结构。这些量子威尔斯比人的头发细5万倍。我们还必须了解限制发光和优化LED中许多其他半导体层导电性的工艺。GaN材料和器件的一个主要问题是了解称为位错的缺陷的作用。GaN器件通常生长在蓝宝石或SiC上。因为GaN具有与蓝宝石或SiC中的原子不同的原子间距，所以当GaN在这些材料上生长时形成非常高数量的位错。最近，具有少得多的位错的独立体GaN已经以有限的数量可用。因为它很难种植，所以很贵。然而，该材料的两家生产商Samsung Corning和Lumilog免费向我们提供了一些这种材料，以便我们可以优化GaN发光结构的生长：蓝色和绿色。这是一个很好的机会来做这件事。据我们所知，世界上还没有人在GaN衬底上生长出绿色LED。这项研究不仅将生产蓝色和绿色LED，还将帮助我们了解GaN LED中位错的作用。

项目成果

Atom probe provides evidence to question InGaN cluster theory

原子探针为质疑 InGaN 团簇理论提供了证据

• 发表时间: 2007
• 期刊: Compound Semiconductor
• 作者: Galtrey M.

High quantum efficiency InGaN/GaN structures emitting at 540 nm

• DOI: 10.1002/pssc.200565252
• 发表时间: 2006-06
• 期刊: Physica Status Solidi (c)
• 作者: D. Graham;P. Dawson;M. J. Godfrey;M. Kappers;P. Costa;M. E. Vickers;R. Datta;C. Humphreys;E. Thrush

Mechanisms of bending of threading dislocations in MOVPE-grown GaN on (0001) sapphire

(0001) 蓝宝石上 MOVPE 生长的 GaN 中穿透位错的弯曲机制

• DOI: 10.1002/pssc.200565369
• 发表时间: 2006
• 期刊: physica status solidi c
• 作者: Datta R

Response to "Comment on 'Three-dimensional atom probe studies of an InxGa1-xN/GaN multiple quantum well structure: assessment of possible indium clustering'" [Appl. Phys. Lett. 91, 176101 (2007)]

回应“对‘InxGa1-xN/GaN 多量子阱结构的三维原子探针研究的评论：对可能的铟簇的评估’”[Appl.

• DOI: 10.1063/1.2783977
• 发表时间: 2007
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Galtrey M

Recombination mechanisms in heteroepitaxial non-polar InGaN/GaN quantum wells

异质外延非极性InGaN/GaN量子阱中的复合机制

• DOI: 10.1063/1.4731730
• 发表时间: 2012
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: Badcock T