Nanowire‐based InGaN light‐emitting diodes (nanoLEDs) have progressed to being the most efficient LEDs ever made at extremely small lateral sizes, and have the added benefits of highly directional emission and extremely narrow bandwidth. Augmented reality headsets and other A/R display applications will require displays that combine these properties with low‐cost and high yield manufacturing.

Information DisplayVolume 38, Issue 6 p. 1-40 Complete IssueFree Access Complete Issue First published: 14 November 2022 https://doi.org/10.1002/msid.1358AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Volume38, Issue6November/December 2022Pages 1-40 RelatedInformation

We demonstrate the use of Nitride semiconductors as the light emitting layer in a series of devices, from Visible emitting LEDs, to far‐UVC LEDs and novel light emitting devices.

We demonstrate a bottom‐up approach to the construction of micro‐LEDs as small as 150 nm in lateral dimension. Molecular beam epitaxy (MBE) is used to fabricate such nanostructured LEDs from InGaN, from the blue to red regions of the spectrum, providing a single material set useful for an entire RGB display.

We demonstrate a bottom‐up approach to the construction of micro‐LEDs as small as 150nm in lateral dimension. Molecular Beam Epitaxy (MBE) is used to fabricate such nanostructured LEDs from InGaN, from the blue to red regions of the spectrum, providing a single material set useful for an entire RGB display.

A Multi‐plane Head‐Up Display (MHUD) using the spectral and angular selectivity of Bragg Grating is presented. Most of today's automotive HUDs display information at a short distance, about 2 meters. However, a key challenge of augmented reality is to have a longer projection distance to superimpose graphics on the external landscape, without parallax issues, while keeping vehicle information at a shorter distance. As a result, the HUD needs to have at least two image planes. Existing methods to build such a multiplane lightfield HUD are complex and bulky. In this paper, we propose a new principle, using a dual PGU an then a single PGU, fitted with HOE working with the spectral dimension of the light.

Diffractive optics such as holographic optical elements (HOEs) can provide transparent and narrow band components with arbitrary incident and diffracted angles for near‐to‐eye commercial electronic products for augmented reality (AR), virtual reality (VR), and smart glass applications. In this paper, we will summarize the operational parameters and general optical geometries relevant for near‐to‐eye displays, the holographic substrates available for these applications, and their performance characteristics and ease of manufacture. We will compare the holographic substrates available in terms of fabrication, manufacturability, and end‐user performance characteristics. Luminit is currently emplacing the manufacturing capacity to serve this market, and this paper will discuss the capabilities and limitations of this unique facility.

Augmented reality (AR) and heads up display (HUD) applications overlap images directly on the user's field of view. To achieve that, optical components with high optical performance and versatility are required. Also, the optical elements must allow an unrestricted view of the world. Traditional optical elements as limited by laws of refraction and reflection, are not versatile, and reduce the transmittance of the devices worn by the AR user. In this paper, we discuss the transparent holographic components' operation parameters and general optical geometries relevant for HUDs, the holographic substrata available for these applications, their performance characteristics and manufacturability.

Semiconductor nanocrystals are being developed with increasingly complex shapes and geometries, often featuring complex shell structures. One aims to characterize these structures by different probes, beyond electronic spectroscopies. Vibrational spectroscopy is a useful tool to probe the phononic structure, but the commonly used frequency-domain methods can be plagued by artifacts due to charge-trapping dynamics. To circumvent these issues, coherent phonons may be measured in the time domain via excitonic state-resolved pump/probe spectroscopy. These measurements reveal several new observations on phononic processes, focusing on model systems of radially graded alloys of core/shell nanocrystals: CdSeCdxZn1-xS. The main new observation is frequency changes to the longitudinal optical phonon at high energy due to electronic mixing. This new, softened phonon mode appears via previously unobserved biexcitonic signals. The state-resolved measurements reveal insights into how the shelling process controls excitonic polarization, carrier trapping, and perturbations to sphericity.

Information DisplayVolume 34, Issue 2 p. 4-4 Guest EditorialFree Access The Race for Dominance: OLED or LCOS Microdisplays in Augmented and Virtual Reality Seth Coe-Sullivan, Seth Coe-SullivanSearch for more papers by this author Seth Coe-Sullivan, Seth Coe-SullivanSearch for more papers by this author First published: 01 March 2018 https://doi.org/10.1002/j.2637-496X.2018.tb01066.xAboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume34, Issue2March-April 2018Pages 4-4 RelatedInformation

A Windshield Head‐Up Display (WHUD) using an embedded optical thin film to improve the system efficiency is presented.Most of today's WHUDs, including the most advanced devices, use the windshield as a simple half‐mirror, so that the main part of the optical flow is not reflected toward the eye‐box.Even with recent work, aiming to increase the optical efficiency of the Picture Generating Unit, or the set of mirrors or light‐guides, reflectance efficiency is not greater than 20%.Experiments performed on the first prototype using Transparent Holographic Optical Components show an optical efficiency of 85%.This result will open the way for a more compact green product device (with a huge reduction in power consumption).

Diffractive optics such as holographic optical elements (HOEs) can provide transparent and narrow band components with arbitrary incident and diffracted angles for near-to-eye commercial electronic products for augmented reality (AR), virtual reality (VR), and smart glass applications. In this paper, we will summarize the operational parameters and general optical geometries relevant for near-to-eye displays, the holographic substrates available for these applications, and their performance characteristics and ease of manufacture. We will compare the holographic substrates available in terms of fabrication, manufacturability, and end-user performance characteristics. Luminit is currently emplacing the manufacturing capacity to serve this market, and this paper will discuss the capabilities and limitations of this unique facility.

Quantum dots (QDs) have been appearing in greater numbers of commercial display products since their first appearance in 2013 Sony Triluminous TVs. Since then, QD-based liquid crystal displays have been found in tablets, laptops, monitors, and TVs, with almost every major TV brand either launching TV product or showing demonstrations at major trade shows. Here we review the major technical innovations that enabled QDs to enter the LCD market, their penetration into display market segments, and the material and integration options available to display system designers. Finally, we will attempt to look forward at how this technology will continue to develop into a pervasive feature of display technology, both LCDs and emissive displays.

The interface of semiconductor nanocrystals is a critical factor for determining-their performance in light emissive applications: Traditional nanocrystals have an abrupt termination of the core/shell interface. Recent synthetic work has focused upon developing graded core/shell interfaces via alloying. Here, we employ femtosecond state resolved pump/probe spectroscopy, temperature-dependent photoluminescence spectroscopy, and a microscopic theory of-interfacial charge trapping to reveal the manner in which a graded interface controls the main optical gain metrics: threshold, bandwidth, and lifetime in the CdSe/Cd,Zn,S tore/shell system. Photoluminescence spectroscopy in conjunction with semiclassical electron transfer theory reveals the absence of an interfacial electronic state. This absence of a surface/interfacial state is unique to these nanocrystals with a graded shell structure, enabling trap free performance. Excitonic state-resolved pump/probe spectroscopy reveals that the higher excitons do not have the same symmetries as spherical CdSe nanocrystals, thereby enabling increased bandwidth. These pump/probe experiments further reveal the unique electronic structure of-the band-edge biexciton which enables single exciton gain in these nanocrystal systems. Finally, the long gain lifetimes are discussed in light of the absence of a surface/interfacial electronic state. These experiments provide the first direct view of how interfacial electronic structure can be probed and understood so as to optimize their performance for light emission and optical gain for the metrics of threshold, bandwidth, and lifetime.

Currently, an exemption to the European Restriction of Hazardous Substances Directive (2011/65/EU) (RoHS2) is in place to enable manufacturers to bring to the market cadmium‐based quantum dot downconversion material in lighting and displays. The II‐VI downconversion materials (e.g. quantum dots), due to their narrowband, tunable, stable and efficient properties, will provide consumer products with the superior performance, efficiency, and net benefit to the environment for which there currently is no beneficial substitute available. In lighting, narrowband emission translates to warmer light sources with 20‐40% greater efficacy. Such products have already been placed on the market in the US. In the display market, narrowband emission translates to televisions, monitors, tablets and cellphones that can achieve 100% of color gamut (as defined by NTSC). This property has the added benefit of increased light throughput through the display, which can in turn reduce energy consumption for identical performance displays by 20% or more.While the cadmium selenide based QDs contain small quantities of cadmium, the net life cycle reductions to energy consumption, carbon emissions, and cadmium waste and emissions are compelling and outlined below. In addition, these new materials will reduce dependency on several EC recognized critical materials such as yttrium, europium, and indium. The net benefit to the environment is due to the system level increase in efficiency that is achieved using the II‐VI downconversion materials, due to their narrowband, tunable, and efficient nature.

Assuming that large color gamut and therefore better color reproducibility will be a highly desired feature of all displays as we look to the near future, we make the case in this paper that quantum dots (QDs) are currently the down-conversion technology of choice that will allow liquid crystal display makers to cost-effectively reach and exceed 100% of the NTSC (National Television Standard Committee) and Adobe RGB color standards while achieving maximum system efficiency. We will discuss in detail the numerous fundamental advantages of QDs over phosphors, along with their scientific origins, and make the case that QDs are the ultimate light generating material for next-generation displays.

Cathodoluminescent imaging of the visible light emitted from quantum dots is reported. The shape and uniformity of individual particles is observed in the scanning transmission electron microscope image, and the image of the particles created from their visible light collected simultaneously is shown. Visible light images of the 13 nm sized particles are reported for clusters of particles. The emission spectrum collected from small clusters of quantum dots is also reported.