Demonstration of relaxed InGaN-based red LEDs grown with high active region temperature

Author(s):  
Philip Chan ◽  
Vincent Rienzi ◽  
Norleakvisoth Lim ◽  
Hsun-Ming Chang ◽  
Michael J. Gordon ◽  
...  
2008 ◽  
Vol 16 (1) ◽  
Author(s):  
P. Karbownik ◽  
R. Sarzała

AbstractRoom-temperature (RT) continuous-wave (CW) operation of the 405-nm ridge-waveguide (RW) InGaN/GaN quantum-well diode lasers equipped with the n-type GaN substrate and two contacts on both sides of the structure has been investigated with the aid of the comprehensive self-consistent simulation model. As expected, the mounting configuration (p-side up or down) has been found to have a crucial impact on the diode laser performance. For the RT CW threshold operation of the otherwise identical diode laser, the p-side up RW laser exhibits as high as nearly 68°C maximal active-region temperature increase whereas an analogous increase for the p-side down laser was equal to only 24°C. Our simulation reveals that the lowest room-temperature lasing threshold may be expected for relatively narrow and deep ridges. For the structure under consideration, the lowest threshold current density of 5.75 kA/cm2 has been determined for the 2.2-μm ridge width and the 400-nm etching depth. Then, the active-region temperature increase was as low as only 24 K over RT. For wider 5-μm ridge, this increase is twice higher. An impact of etching depth is more essential for narrower ridges. Quite high values (between 120 and 140 K) of the characteristic parameter T0 convince very good thermal properties of the above laser.


2020 ◽  
Vol 36 (3) ◽  
pp. 69-90
Author(s):  
S. N. Chornogor ◽  
◽  
N. N. Kondrashova ◽  

2020 ◽  
Author(s):  
Zenghui Yang

Quantum mechanics/molecular mechanics (QM/MM) methods partition the system into active and environmental regions and treat them with different levels of theory, achieving accuracy and efficiency at the same time. Adaptive-partitioning (AP) QM/MM methods allow on-the-fly changes to the QM/MM partitioning of the system. Many of the available energy-based AP-QM/MM methods partition the system according to distances to pre-chosen centers of active regions. For such AP-QM/MM methods, I develop an adaptive-center (AC) method that allows on-the-fly determination of the centers of active regions according to general geometrical or potential-related criteria, extending the range of application of energy-based AP-QM/MM methods to systems where active regions may occur or vanish during the simulation.


Sign in / Sign up

Export Citation Format

Share Document