Strain relaxation of InGaN/GaN multi-quantum well light emitters via nanopatterning

Effect of AlGaN interlayer on the GaN/InGaN/GaN/AlGaN multi-quantum wells structural properties toward red light emission

“…However, it is worth noticing that in the corresponding inplane grazing incidence diffraction measurement at around (101 ̅ 0) GaN template, for all samples, neither broadening nor splitting of the peak can be visualized and this has been attributed to a local partial strain relaxation. 20 Therefore, both the increase of the AlGaN thickness and the MQW stack local composition variations are sources of partial strain relaxation in these heterostructures leading to the observed structural degradation. So this local strain relaxation takes place in different ways without the conventional formation of misfit dislocations as the QWs are below the critical thickness for plastic relaxation in the This is the author's peer reviewed, accepted manuscript.…”

“…Bragg reflections were used respectively to determine the mean c out-off plane and a in-plane lattice constants of the MQW stack according to references. [18][19][20] In order to verify if in plane local relaxation is present in our samples, a direct measurement around the (101 ̅ 0) GaN diffraction peak has been also performed. 21 The surface morphology of all the samples was investigated by Atomic Force Microscopy…”

Garnet-Type Nanophosphors for White LED Lighting

“…This phosphor powder, encapsulated in an epoxy or silicone resin, is placed above the chip (remote phosphor) and partially absorbs the blue light to down-convert in the yellow range thus leading to white light emissions. However, the micron-size of YAG:Ce phosphors induces several drawbacks: (1) backscattering toward the blue chip, both reducing the external efficiency of the wLEDs at around 60% and damaging gradually the chip, thus reducing the device lifetime (Narendran et al, 2005); (2) need to encapsulate the phosphors in a resin to obtain a mechanically stable layer, the binder leading to accelerated aging of the wLEDs (Yang et al, 2012;Hang et al, 2013); (3) poor coupling with blue nanostructured chips that are now emerging, such as InGaN nanowire arrays for micro-displays (Ley et al, 2019). Moreover, with regard to the latter point in particular, the use of micron-sized phosphors is unsuitable to implement additive manufacturing techniques, which are quickly rising as a potential benefit to wLED developments.…”

Twofold advantage of gas bubbling for the advanced solvothermal preparation of efficient YAG:Ce nanophosphors

“…Recent developments include elaboration of micro-LEDs and semiconductor nanostructuration. 1,2 Phosphor elaboration is also a key factor in optimizing the efficiency and stability of phosphor-converted LED (pc-LED) lighting devices. 3,4,5,6 In this context and for the development of new applications, particularly for miniaturization involving solution-based deposition techniques (e.g.…”