In this study, we investigated the temperature-dependent photoluminescence characteristics of green InGaN/GaN multiple quantum wells (MQWs) with InGaN/GaN pre-wells and InGaN pre-layers, and the electroluminescence properties of the corresponding mini-LEDs were fabricated and studied. According to the fitting results of the temperature-dependent photoluminescence spectra obtained by the Vaishini and Arrhenius models, the S-shaped temperature-dependent peak energies of green InGaN/GaN MQWs grown on pre-wells and pre-layers indicated that these peaks originated from the localized state, and better crystal quality could be found in the MQWs with pre-layers. Moreover, we compared the electroluminescence properties of green mini-LEDs. These results demonstrate the advantages of growing green MQWs with an InGaN prelayer.

A pre-strained structure is used to mitigate the quantum confined stark effect in green micro-light-emitting diodes ( $\mu $ LEDs) for visible light communication, thus increased luminous efficiency and modulation bandwidth. The photocarriers in the pre-layer do not participate in radiative recombination, which increased responsivity when turned-on green $\mu $ LEDs worked as photodetectors. Peak responsivity up to 0.56 and 0.43 A/W at −5 and 3.5 V bias was achieved, respectively. And the decreased capacitance improved the receiving bandwidth of $\mu $ LEDs. The single green $\mu $ LED with pre-layer could act as transceiver and achieves bidirectional rates of 1.1 Gbps.

In this article, we experimentally and quantitatively investigate the luminance attenuation for red, green, and blue mini light-emitting diodes (LEDs), and the optical crosstalk in the RGB mini-LED array under different working currents via the microscopic hyperspectral imaging technique. The evaluation metrics of luminance attenuation for one single mini-LED subpixel and luminance influence among all three colored mini-LEDs are well defined to quantitatively describe the optical crosstalk among three mini-LED subpixels in the array. We also compare the size-dependent behaviors of luminance attenuation for blue and green mini-LEDs with an emission peak of about 465 nm and 529 nm, respectively. The minimum pixel pitch of blue and green mini-LEDs with different chip sizes is obtained through optical simulation based on LightTools software, so that the optical crosstalk can be reduced. Finally, we believe that this study could provide a useful guidance for selecting suitable working current conditions while driving the mini-LED display with suitable pixel size and pixel pitch to reduce both the optical and color crosstalk in the mini-LED display.

In this study, we fabricated deep-ultraviolet light-emitting diodes (DUV-LEDs) with Al2O3 films of 0-, 130-, and 255-nm via atomic layer deposition (ALD). In addition, the effects of the passivation layers on the DUV-LEDs were systematically investigated. The current–voltage characteristics of these samples revealed the passivating effect of the Al2O3 ALD films on the DUV-LEDs. By analyzing the external quantum efficiency (EQE) at room temperature using the ABC + ${f}\,{(n)}$ model, the differences in the physical mechanisms of the Al2O3 ALD film on DUV-LEDs were determined. The measurements of the electroluminescence (EL) and far-field radiation patterns (EQE, light output power (LOP), and radiation patterns) showed that ALD can enhance the performance of DUV-LEDs, particularly DUV-LEDs with a 130-nm Al2O3 ALD passivation layer. Moreover, the aging test and failure ratio of these DUV-LEDs under humidity exposure (85 °C/85% RH) indicated the specific effect of these Al2O3 ALD films on the reliability of DUV-LEDs.

In this study, green micro-light-emitting diodes (μ-LEDs) with Al₂O₃ layers of varying thicknesses (0, 30, 60, and 90 nm) was fabricated using atomic layer deposition (ALD) technology. The optoelectronic characteristics of devices was measured and investigated. Current–voltage (I–V) measurements indicate that the ALD passivation layer effectively reduces leakage current. By applying the ABC + f(n) model to analyze external quantum efficiency, the internal physical mechanisms that the ALD passivation layer enhances the optoelectronic performance of green μ-LEDs was identified. Optical simulations demonstrated the transmittance relationship for different ALD passivation layer thicknesses, explaining improvements of light extraction efficiency. Furthermore, aging tests confirmed that the ALD passivation layer significantly increases the stability of green μ-LEDs. These findings offer valuable insights for enhancing the luminous efficiency and reliability of green μ-LEDs.