Efficiency enhancement of UV/blue light emitting diodes via nanoscaled epitaxial lateral overgrowth of GaN on a SiO2 nanorod-array patterned sapphire substrate

Highly Efficient and Bright LEDs Overgrown on GaN Nanopillar Substrates

“…Since the film on NP template bears less strain, consequently we can expect that the GaN-based LED grown on such template have weaker quantum-confined Stark effect (QCSE) [28]. LED devices with a chip size of 350 × 350 mm 2 were then fabricated from the completed epitaxial structures grown on sapphire with and without GaN NPs.…”

Light Output Enhancement of GaN-Based Light-Emitting Diodes by Optimizing SiO2 Nanorod-Array Depth Patterned Sapphire Substrate

“…Such behaviors often happened in the NELOG method on a nanoscale patterned sapphire substrate. 16) On the other hand, when we increased the nanorod height further, we observed that the 300 nm nanorod array is more difficult to coalesce owing to the height of the oxide nanorod, and thus also leads to more coalescent defects. Since these two mechanisms (activation of NELOG and coalescence of GaN) dominate in deep and shallow nanorods, respectively, it is natural to consider that the 200 nm nanorod array exhibits intermediate characteristics and has the highest crystal quality, which is the case in the actual wafer growth.…”

The effect of free-standing GaN substrate on carrier localization in ultraviolet InGaN light-emitting diodes

“…It is obvious that compared with the UV-LEDs on sapphire samples, the UV-LEDs on FS-GaN showed a quite uniform Raman peak distribution over the region scanned, where the STD for the UV-LEDs on FS-GaN is only 0.18 cm -1 . Consequently, we can expect that the UV-LEDs grown on the FS-GaN substrate have weaker quantum-confined Stark effect (QCSE) and small curvature [12]. …”