The advantage of GaN power devices in terms of performance is no longer hype but a reality that has empowered many power supply designers to build new applications that are more efficient, compact and able to operate in harsher environmental conditions. With a projected market size of U.S. $600 million in 2020 and a CAGR of 80% to 2020, many new players have entered the field and are introducin...

Recent advances in deep generative models give us new perspective on modeling highdimensional, nonlinear data distributions. Especially the GAN training can successfully produce sharp, realistic images. However, GAN sidesteps the use of traditional maximum likelihood learning and instead adopts an two-player game approach. This new training behaves very differently compared to ML learning. Ther...

We investigate the interactions between hydrogen and dopant impurities in GaN, using state-of-the-art first-principles calculations. Our results for energetics and migration reveal a fundamental difference in the behavior of hydrogen between p-type and n-type material; in particular, we explain why hydrogen concentrations in n-type GaN are low, and why hydrogen has a beneficial effect on accept...

The past year has yielded many insights and a few surprises in the field of axonal regeneration. The identification of oligodendrocyte-myelin glycoprotein as an inhibitor of axonal growth, and the discovery that the three major myelin-associated inhibitors of CNS regeneration share the same functional receptor, has launched a new wave of studies that aim to identify the signaling components of ...

Thick c-plane unintentional doped and iron-doped GaN substrates were grown by hydride vapor phase epitaxial technique on sapphire substrates. The morphology and crystalline quality of the freestanding samples show no evident degradation due to iron doping. Low-temperature photoluminescence measurements show reduction of the exciton-bound to neutral impurities band intensities with iron doping i...

An innovative method to filter out potentially unstable and unreliable RDSON drifting wafers is demonstrated in GaN-based power devices. Its concept is described and the correlation between screening test and long-term reliability data in terms of RDSON stability is also presented. In addition, we verify that this screening method can predict continuous dynamic RDSON characteristics, which is d...

We utilize the recently demonstrated orders of magnitude enhancement of extremely nondegenerate two-photon absorption in direct-gap semiconductor photodiodes to perform scanned imaging of three-dimensional (3D) structures using IR femtosecond illumination pulses (1.6 µm and 4.93 µm) gated on the GaN detector by sub-gap, femtosecond pulses. While transverse resolution is limited by the usual ima...

Image classification datasets are often imbalanced, characteristic that negatively affects the accuracy of deeplearning classifiers. In this work we propose balancing GANs (BAGANs) as an augmentation tool to restore balance in imbalanced datasets. This is challenging because the few minority-class images may not be enough to train a GAN. We overcome this issue by including during training all a...

Significant enhancement in the light output from GaN-based green light-emitting diodes (LEDs) was achieved with a hemicylindrical grating structure on the top layer of the diodes. The grating structure was first optimized by the finite-difference time-domain (FDTD) method, which showed that the profile of the grating structure was critical for light extraction efficiency. It was found that the ...

The effects on the lattice parameters due to incorporation of impurities in GaN are evaluated using firstprinciples pseudopotential-density-functional calculations. Both the size effect, due to the relaxation of host atoms around the impurity, and the deformation-potential effect, due to placing free carriers in the conduction or valence band, are investigated. The incorporation of silicon and ...