Real-Time Tunable Gas Sensing Platform Based on SnO Nanoparticles Activated by Blue Micro-Light-Emitting Diodes.

Micro-light-emitting diodes (μLEDs) have gained significant interest as an activation source for gas sensors owing to their advantages, including room temperature operation and low power consumption. However, despite these benefits, challenges still exist such as a limited range of detectable gases and slow response. In this study, we present a blue μLED-integrated light-activated gas sensor array based on SnO nanoparticles (NPs) that exhibit excellent sensitivity, tunable selectivity, and rapid detection with micro-watt level power consumption.

Advanced Mechanical Transfer of Micro-LEDs Enabled by Structurally Modified Wide Sapphire Nanomembranes through Thermal Reflow of Photoresist.

Micro light-emitting diodes (micro-LEDs) are pivotal in next-generation display technologies, driven by the need for high pixel density. This study introduces a novel methodology utilizing wide sapphire nanomembranes (W-SNM) as a dual-purpose template for high-quality epitaxial growth and the mechanical lift-off of individual micro-LEDs. Micro-LEDs grow individually on W-SNM, obviating the chip singulation process.

Enhancing Performance of Ultraviolet C Photodetectors Through Single-Domain Epitaxy of Monoclinic β-Ga O Films and Tailored Anti-Reflection Coating.

Implementing high-performance ultraviolet C photodetectors (UVC PDs) based on β-Ga O films is challenging owing to the anisotropic crystal symmetry between the epitaxial films and substrates. In this study, highly enhanced state-of-the-art photoelectrical performance is achieved using single-domain epitaxy of monoclinic β-Ga O films on a hexagonal sapphire substrate. Unlike 3D β-Ga O films with twin domains, 2D β-Ga O films exhibit a single domain with a smooth surface and low concentration of point defects, which enable efficient charge separation by suppressing boundary-induced recombination.

Technological Breakthroughs in Chip Fabrication, Transfer, and Color Conversion for High-Performance Micro-LED Displays.

The implementation of high-efficiency and high-resolution displays has been the focus of considerable research interest. Recently, micro light-emitting diodes (micro-LEDs), which are inorganic light-emitting diodes of size <100 µm , have emerged as a promising display technology owing to their superior features and advantages over other displays like liquid crystal displays and organic light-emitting diodes. Although many companies have introduced micro-LED displays since 2012, obstacles to mass production still exist.

Self-Assembled Size-Tunable Microlight-Emitting Diodes Using Multiple Sapphire Nanomembranes.

Microlight-emitting diode (Micro-LED) is the only display production technology capable of meeting the high-performance requirements of future screens. However, it has significant obstacles in commercialization due to etching loss and efficiency reduction caused by the singulation process, in addition to expensive costs and a significant amount of time spent on transfer. Herein, multiple-sapphire nanomembrane (MSNM) technology has been developed that enables the rapid transfer of arrays while producing micro-LEDs without the need for any singulation procedure.

α-Gallium Oxide Films on Microcavity-Embedded Sapphire Substrates Grown by Mist Chemical Vapor Deposition for High-Breakdown Voltage Schottky Diodes.

α-Gallium oxide, with its large band gap energy, is a promising material for utilization in power devices. Sapphire, which has the same crystal structure as α-GaO, has been used as a substrate for α-GaO epitaxial growth. However, lattice and thermal expansion coefficient mismatches generate a high density of threading dislocations (TDs) and cracks in films.

A discrete core-shell-like micro-light-emitting diode array grown on sapphire nano-membranes.

A discrete core-shell-like micro-light-emitting diode (micro-LED) array was grown on a 100 nm-thick sapphire nano-membrane array without harmful plasma etching for chip singulation. Due to proper design for the sapphire nano-membrane array, an array of multi-faceted micro-LEDs with size of 4 μm × 16 μm was grown. Threading dislocation density in the micro-LED formed on sapphire nano-membrane was reduced by 59.

Highly polarized photoluminescence from c-plane InGaN/GaN multiple quantum wells on stripe-shaped cavity-engineered sapphire substrate.

Highly polarized photoluminescence (PL) from c-plane InGaN/GaN multiple quantum wells (MQWs) grown on stripe-shaped cavity-engineered sapphire substrate (SCES) was realized. The polarization ratio was as high as 0.74 at room temperature.

Solid-Phase Epitaxial Growth of an Alumina Layer Having a Stacking-Mismatched Domain Structure of the Intermediate γ-Phase.

Solid-phase epitaxy (SPE), a solid-state phase transition of materials from an amorphous to a crystalline phase, is a convenient crystal growing technique. In particular, SPE can be used to grow α-AlO epitaxially with a novel structure that provides an effective substrate for improved performance of light-emitting diodes (LEDs). However, the inevitable two-step phase transformation through the γ-AlO phase hinders the expected improved crystallinity of α-AlO, and thereby further enhancement of LED performance.

Microstructured Air Cavities as High-Index Contrast Substrates with Strong Diffraction for Light-Emitting Diodes.

Two-dimensional high-index-contrast dielectric gratings exhibit unconventional transmission and reflection due to their morphologies. For light-emitting devices, these characteristics help guided modes defeat total internal reflections, thereby enhancing the outcoupling efficiency into an ambient medium. However, the outcoupling ability is typically impeded by the limited index contrast given by pattern media.

Electrical spin injection from room-temperature ferromagnetic (Ga, Mn)N in nitride-based spin-polarized light-emitting diodes.

We present the electrical spin injection from room-temperature ferromagnetic (Ga, Mn)N in nitride-based spin-polarized light-emitting diodes. The electroluminescence spectra from the spin LED indicate the existence of the spin polarization via optical polarization of emitted light up to room temperature. This demonstrates that the spin injection from the (Ga, Mn)N layer into (In, Ga)N quantum wells was achieved persisting up to room temperature by comparing it with the magnetic field dependence of the Hall resistance, which is proportional to the out-of-plane magnetization.