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Herein, a selective passivation of p‐GaN via hydrogen plasma treatment for InGaN single‐quantum‐well (SQW) red light‐emitting diodes (LEDs) is reported. Insulating regions are formed on the p‐GaN top surface via hydrogen plasma treatment, suppressing current injection beneath the p‐pad and along the mesa perimeter to increase light output and mitigate non‐radiative recombination. The fabricated LEDs demonstrate a high on‐wafer light output power density of >88 mW cm−2, a peak on‐wafer external quantum efficiency of 0.65%, and on‐wafer wall‐plug efficiency of 0.41% with a 645 nm peak emission wavelength at 10 mA (7.2 A cm−2) current injection. Further, the temperature dependence of InGaN SQW red LEDs is compared with their AlGaInP counterparts. InGaN SQW red LEDs exhibit a high characteristic temperature of 208 K and a small redshift coefficient of 0.072 nm K−1 at 72 A cm−2 current injection, which are almost 3 and 2 times better than the characteristics of AlGaInP red LEDs, respectively. [ABSTRACT FROM AUTHOR]

In this study, we have demonstrated the potential of InGaN-based red micro-LEDs with single quantum well (SQW) structure for visible light communication applications. Our findings indicate the SQW sample has a better crystal quality, with high-purity emission, a narrower full width at half maximum, and higher internal quantum efficiency, compared to InGaN red micro-LED with a double quantum wells (DQWs) structure. The InGaN red micro-LED with SQW structure exhibits a higher maximum external quantum efficiency of 5.95% and experiences less blueshift as the current density increases when compared to the DQWs device. Furthermore, the SQW device has a superior modulation bandwidth of 424 MHz with a data transmission rate of 800 Mbit/s at an injection current density of 2000 A/cm2. These results demonstrate that InGaN-based SQW red micro-LEDs hold great promise for realizing full-color micro-display and visible light communication applications. [ABSTRACT FROM AUTHOR]

In this work, we present the characterization of red InGaN/GaN multiple-quantum-well (MQW) light-emitting diode structures. The optical properties of two MQW structures with different n-GaN underlayer thicknesses (4 and 8 μm) are studied and compared. The results of photoluminescence studies show that a thicker n-GaN layer is beneficial for obtaining higher In content for red MQWs. However, the sample with a thicker n-GaN layer has a poorer internal quantum efficiency, a larger full width at half maximum, and a shorter nonradiative recombination time, implying that there are stronger In-content fluctuations and more defects. Furthermore, red MQWs with higher In content are shown to exhibit more deep localized states. Our findings imply that in order to achieve high-efficiency InGaN MQWs for red emission, enhancing the uniformity of In-content distribution in the active region and decreasing nonradiative recombination centers are critical challenges. [ABSTRACT FROM AUTHOR]

Here, we report highly efficient InGaN-based red light-emitting diodes (LEDs) grown on conventional c-plane-patterned sapphire substrates. An InGaN single quantum well active layer provides the red spectral emission. The 621-nm-wavelength LEDs exhibited high-purity emission with a narrow full-width at half-maximum of 51 nm. The packaged LED's external quantum efficiency, light-output power, and forward voltage with a 621 nm peak emission wavelength at 20 mA (10.1 A/cm2) injection current were 4.3%, 1.7 mW, and 2.96 V, respectively. This design development represents a valuable contribution to the next generation of micro-LED displays. [ABSTRACT FROM AUTHOR]

Here, we report highly efficient InGaN-based red light-emitting diodes (LEDs) grown on conventional c-plane-patterned sapphire substrates. An InGaN single quantum well active layer provides the red spectral emission. The 621-nm-wavelength LEDs exhibited high-purity emission with a narrow full-width at half-maximum of 51 nm. The packaged LED's external quantum efficiency, light-output power, and forward voltage with a 621 nm peak emission wavelength at 20 mA (10.1 A/cm2) injection current were 4.3%, 1.7 mW, and 2.96 V, respectively. This design development represents a valuable contribution to the next generation of micro-LED displays. [ABSTRACT FROM AUTHOR]

We demonstrated amber InGaN $47\times 47\,\,\mu \text{m}^{{2}}$ micro-light-emitting diodes ($\mu $ LEDs) with the peak wavelength of 606 nm and full-width at maximum (FWHM) of 50 nm at 20 A/cm2. The amber $\mu $ LEDs exhibited a 33-nm blue-shift of the peak wavelength and obtain broader FWHMs to approximately 56 nm at 5 to 100 A/cm2. The peak on-wafer external quantum efficiency was 0.56% at 20 A/cm2. The characteristic temperature was 50–80 K at 20 to 60 A/cm2 but increased to 120–140 K at 80 to 100 A/cm2. The strong increase in the characteristic temperature from 60 to 80 A/cm2 could mainly be attributed to the saturation of the Shockley-Read-Hall non-radiative recombination at high current densities. [ABSTRACT FROM AUTHOR]

We investigated the effects of size on electrical and optical properties of InGaN-based red light-emitting diodes (LEDs) by designing rectangular chips with different mesa lengths. Larger chips exhibited lower forward voltages because of their lower series resistances. A larger chip helped to realize a longer emission wavelength, narrower full-width at half maximum, and higher external quantum efficiency. However, temperature-dependent electroluminescence measurements indicated that larger chips are detrimental to applications where high temperature tolerance is required. In contrast, a smaller red LED chip achieved a high characteristic temperature of 399 K and a small redshift tendency of 0.066 nm K−1, thus showing potential for temperature tolerant lighting applications. [ABSTRACT FROM AUTHOR]

This work investigates the influence of residual stress on the performance of InGaN-based red light-emitting diodes (LEDs) by changing the thickness of the underlying n-GaN layers. The residual in-plane stress in the LED structure depends on the thickness of the underlying layer. Decreased residual in-plane stress resulting from the increased thickness of the underlying n-GaN layers improves the crystalline quality of the InGaN active region by allowing for a higher growth temperature. The electroluminescence intensity of the InGaN-based red LEDs is increased by a factor of 1.3 when the thickness of the underlying n-GaN layer is increased from 2 to 8 μm. Using 8-μm-thick underlying n-GaN layers, 633-nm-wavelength red LEDs are realized with a light-output power of 0.64 mW and an external quantum efficiency of 1.6% at 20 mA. The improved external quantum efficiency of the LEDs can be attributed to the lower residual in-plane stress in the underlying GaN layers. [ABSTRACT FROM AUTHOR]

We report internal quantum efficiency enhancement of thin p-GaN green quantumwell structure using self-assembled Ag nanoparticles. Temperature dependent photoluminescence measurements are conducted to determine the internal quantum efficiency. The impact of excitation power density on the enhancement factor is investigated. We obtain an internal quantum efficiency enhancement by a factor of 2.3 at 756 W/cm², and a factor of 8.1 at 1 W/cm². A Purcell enhancement up to a factor of 26 is estimated by fitting the experimental results to a theoretical model for the efficiency enhancement factor. [ABSTRACT FROM AUTHOR]