Session Index

Here we present a dual-gate transistor structure to suppress the dynamic on-resistance increase. The auxiliary gate under a proper fixed voltage is able to induce additional electrons to compensate the channel carrier loss during main gate switching, leading to a lower dynamic on resistance. In this work, we benchmarked the fundamental electrical properties of both single-gate and dual-gate HEMTs. We further extracted the dynamic behaviors by stressing the devices with short pulses. The results suggest a significant improvement of dynamic behaviors of a dual-gate HEMT under a proper bias applied on the auxiliary gate electrode.

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For nitride-based blue and green light-emitting diodes (LEDs), the forward voltages (Vf) are higher due to the large barriers to vertical carrier transport caused by the total polarization discontinuity at multiple quantum well (QW) and quantum barrier interfaces. As we know, the turn-on voltages for blue and green LED are both affected by random alloy fluctuation and V-defect density. In our model, we find that the Vf of the green LEDs is reduced significantly by V-defects, where the smaller polarization barrier at the V-defect sidewall is the major path for lateral carrier injection.

 

AlGaN-based UVC-LED structure has electrochemical (EC) treated porous AlGaN layer. The photoluminescence peak wavelength has a slightly blueshift phenomenon from non-treated LED (274.1nm) to EC-LED (272.4nm) due to the partial strain release in the active layer with embedded porous layer. In electroluminescence (EL) emission spectrum, the intensity for the AlGaN active layer (~270nm) was increased. By forming the conductive porous-AlGaN:Si layer, the EL emission intensity of the EC-LED has 20% enhancement compared to non-treated LED. High light extraction effect of the UVC-LED with porous-AlGaN layer has been studied for the high efficiency UVC-LED applications.

 

In this study, green quantum dot light-emitting diodes (QLEDs) comprised of inorganic/organic hybrid hole injection/transport layers with solution-process was reported. Molybdenum oxide (MoOx) was used as hole injection layer (HIL), Poly-TPD as hole transport layer (HTL) and magnesium doped zinc oxide nanoparticles (Mg0.1Zn0.9O NPs) served as electron transport layer (ETL) prepared by synthesis nanoparticles method were demonstrated. The maximum luminance (Lmax) of the fabricated QLEDs can be up to 138,612 cd/m2 with current efficiency of about 6.72 cd/A.

 

For nitride-based AlGaN LEDs, the potential fluctuations caused by alloy disorder may relax the compressive strain in the lower Al (higher Ga) composition sites. In this paper, the k·p method combined with 3D-DDCC solver is used to study the polarization ratio changes due to the random alloy fluctuation and different Al composition in the buffer layer. When the TM polarization ratio is higher, increasing the Al composition of the buffer layer from 60% to 100%, the polarization ratio decreases from 0.33 to -0.57 due to the increased compressive strain.

 

In order to achieve a better heat dissipation, diamond powder is added into the QDLED package. The results show that the maximum temperature and surface areal temperature can be reduced, but the optical performance will be impacted when mixed with diamond.