Light-Emitting Diodes. (Monographs in Electrical and Electronic Engineering.) By A. A. Bergh and P. J. Dean. Pp. viii+591. (Clarendon: Oxford; Oxford University: London, 1976.) £22.

/pdf/light-emitting-diodes-ubzde6g9qc.pdf

Light-emitting diodes

One-dimensional (1D) ZnO nanostructures have been studied intensively and extensively over the last decade not only for their remarkable chemical and physical properties, but also for their current and future diverse technological applications. This article gives a comprehensive overview of the progress that has been made within the context of 1D ZnO nanostructures synthesized via wet chemical methods. We will cover the synthetic methodologies and corresponding growth mechanisms, different structures, doping and alloying, position-controlled growth on substrates, and finally, their functional properties as catalysts, hydrophobic surfaces, sensors, and in nanoelectronic, optical, optoelectronic, and energy harvesting devices.

/pdf/one-dimensional-zno-nanostructures-solution-growth-and-30xs4d6be7.pdf

One-dimensional ZnO nanostructures: Solution growth and functional properties

Over the past decade, advances in LEDs have enabled the potential for wide-scale replacement of traditional lighting with solid-state light sources. If LED performance targets are realized, solid-state lighting will provide significant energy savings, important environmental benefits, and dramatically new ways to utilize and control light. In this paper, we review LED performance targets that are needed to achieve these benefits and highlight some of the remaining technical challenges. We describe recent advances in LED materials and novel device concepts that show promise for realizing the full potential of LED-based white lighting.

LEDs for Solid-State Lighting: Performance Challenges and Recent Advances

An organic light-emitting diode (OLED) display is disclosed. In one aspect, the display includes a stretchable substrate, a thin film transistor (TFT) formed over the stretchable substrate and including a plurality of electrodes, an OLED electrically connected to the TFT and including a plurality of electrodes, and a plurality of interconnection lines connected to the electrodes of the OLED and the TFT. At least one of the interconnection lines is configured to move in a stretching direction and rotate an electrode selected from the electrodes of the OLED and the TFT connected to the at least one interconnection line.

Organic light-emitting diode display

A light-emitting device package including: a package main body including a cavity and a lead frame including a mounting portion disposed in the cavity and a plurality of terminal portions; a light-emitting device chip mounted on the mounting portion; a plurality of bonding wires for electrically connecting the plurality of terminal portions and the light-emitting device chip; a light-transmitting encapsulation layer filled in the cavity; and a light-transmitting cap member disposed in the cavity and blocking the encapsulation layer to contact the plurality of bonding wires.

Light emitting device package

We first report on the fabrication of 2 inch wafer-level GaN-based vertical light-emitting diodes (LEDs) by using a multi-functional bonding material system, which is composed of a thick Cu diffusion barrier and a bonding layer. The bonding material system superbly absorbs laser-induced stress and also effectively serves as a barrier to the indiffusion of Sn to the active region. Fully packaged vertical LEDs fabricated with indium tin oxide (ITO)/AgCu contact and the bonding material system give an operating voltage of 3.35 V at 350 mA. After over 1800 h, the operating voltages remain stable, and the reverse currents are in the range 3–8 × 10−7 A at −5 V.

https://iopscience.iop.org/article/10.1088/0268-1242/24/9/092001/pdf

Wafer-level fabrication of GaN-based vertical light-emitting diodes using a multi-functional bonding material system

The authors report on the design and fabrication of high-efficiency GaN-based light emitting diodes (LEDs) with vertical-injection geometry. Based on the analyses of LED test patterns fabricated with various n-electrode dimensions, a design rule for vertical LEDs is proposed. It is found that the suppression of the vertical current under n electrodes and the efficient injection of the spreading current across the n layers are essential to fabricate high-efficiency LEDs. Introduction of the current blocking layer along with well-designed branched n electrodes results in a large enhancement of power efficiency by a factor of 1.9, compared with that of reference LEDs.

Design of high-efficiency GaN-based light emitting diodes with vertical injection geometry

Disclosed is a method of fabricating a light emitting diode (100) comprising the steps of: forming a compound semiconductor layer (145) on a substrate (110), the substrate including a chip region and an isolation region; selectively etching the compound semiconductor layer to form a light emitting structure (120) on the chip region and form a buffer structure (180) on the isolation region; forming a conductive support member (160) on the light emitting structure and the buffer structure; removing the substrate by using a laser lift off process; and dividing the conductive support member into a plurality of chip regions, wherein the buffer structure (180) is spaced apart from the light emitting structure (120)

Light-emitting diode and fabrication method thereof

A light emitting device includes a light emitting structure including a second conduction type semiconductor layer, an active layer, and a first conduction type semiconductor layer, a second electrode layer arranged under the light emitting structure, a first electrode layer having at least portion extending to contact the first conduction type semiconductor layer passing the second conduction type semiconductor layer and the active layer, and an insulating layer arranged between the second electrode layer and the first electrode layer, between the second conduction type semiconductor layer and the first electrode layer, and between the active layer and the first electrode layer, wherein said at least one portion of the first electrode layer contacting the first conduction type semiconductor layer has a roughness.

Light emitting device and light emitting device package thereof

The present invention relates to a light emitting device, a light emitting device package, and a lighting device with the same. The light emitting device includes a light emitting structure including a first conductive type semiconductor layer, an active layer, and a second conductive type semiconductor layer, a second electrode layer formed on an underside of the light emitting structure connected to the second conductive type semiconductor layer electrically, a first electrode layer in contact with the first conductive type semiconductor layer passed through the second conductive type semiconductor layer and the active layer, and an insulating layer formed between the second electrode layer and the first electrode layer, between the second conductive type semiconductor layer and the first electrode layer, and between the active layer and the first electrode layer.

Kwang Ki Choi

Papers

Wafer-level fabrication of GaN-based vertical light-emitting diodes using a multi-functional bonding material system

Design of high-efficiency GaN-based light emitting diodes with vertical injection geometry

Light-emitting diode and fabrication method thereof

Light emitting device and light emitting device package thereof

Light emitting device, light emitting device package, and lighting device with the same