Status of GaN-based green light-emitting diodes

Abstract

GaN-based blue light emitting diodes (LEDs) have undergone great development in recent years, but the improvement of green LEDs is still in progress. Currently, the external quantum efficiency (EQE) of GaN-based green LEDs is typically 30%, which is much lower than that of top-level blue LEDs. The current challenge with regard to GaN-based green LEDs is to grow a high quality InGaN quantum well (QW) with low strain. Many techniques of improving efficiency are discussed, such as inserting AlGaN between the QW and the barrier, employing prestrained layers beneath the QW and growing semipolar QW. The recent progress of GaN-based green LEDs on Si substrate is also reported: high efficiency, high power green LEDs on Si substrate with 45.2% IQE at 35 A/cm2, and the relevant techniques are detailed.

Design and Modeling of Light Emitting Nano-Pixel Structure (LENS) for High Resolution Display (HRD) in a Visible Range

“…Indeed, direct GaN-based green LED emits a narrower spectrum than the phosphor converted green LED. As a result, the direct GaN green has a higher purity green light [13]. Furthermore, the display brightness [14] and its power efficiency (Lumens/Watts) are two essential parameters allowing, or not, outdoor applications and long battery life.…”

Highly pure green light emission of perovskite CsPbBr_3 quantum dots and their application for green light-emitting diodes

“…The solution gave out evenly-distributed and intensive green light. The quantum efficiency of the perovskite CsPbBr 3 QDs solution was about 85%, which was measured by the Quantaurus-QY from HAMAMATSU. The absorption and PL spectra of the QDs in toluene were given in Fig.…”

“…In order to achieve high color rendition (Ra > 80) of white LEDs, the component ratio of green light and red light should be larger. Furthermore, high-purity green light plays an important role in backlight of liquid crystal display [3]. Unfortunately, green GaN-based LEDs suffer from a rapid degradation in efficiency when the emission wavelength is in the range of 500 nm to 600 nm, which is called "green gap" phenomenon [4,5].…”

Deep Electron and Hole Traps in Electron-Irradiated Green GaN/InGaN Light Emitting Diodes

“…Green light emitting diodes (LEDs) based on GaN/InGaN multiquantum-well (MQW) structures continue to of great interest for displays and lighting applications. [1][2][3][4][5] The quality of these LEDs continues to improve and their external quantum efficiency (EQE) is currently 20-30%. 1 However, the efficiency of these LEDs is still inferior compared to blue GaN/InGaN LEDs, a phenomenon generally referred to as the "green gap".…”