scholarly journals GaN-Based Materials for Blue Emitting Device Structures Grown in Multiwafer Planetary® Reactors

Author(s):  
O. Schoen ◽  
D. Schmitz ◽  
M. Heuken ◽  
Holger Juergensen ◽  
M. D. Bremser

Using optimised growth processes for an AIX 2000 HT Planetary® Reactor a high material quality and high potential device yield are demonstrated. Doping levels for GaN single layers from 1·1020 cm−3 free electrons to semi-insulating to 1·1018 cm−3 free holes with state-of-the-art layer resistance uniformities especially for n-type layers are shown. Both AlGaN and GaInN with composition homogeneities of better than 1 nm photoluminescence peak-wavelength standard deviation are displayed. Finally, examination of optically pumped laser action in simple double-hetero structures is quoted to prove the quality of the material.

2020 ◽  
pp. 1-16
Author(s):  
Meriem Khelifa ◽  
Dalila Boughaci ◽  
Esma Aïmeur

The Traveling Tournament Problem (TTP) is concerned with finding a double round-robin tournament schedule that minimizes the total distances traveled by the teams. It has attracted significant interest recently since a favorable TTP schedule can result in significant savings for the league. This paper proposes an original evolutionary algorithm for TTP. We first propose a quick and effective constructive algorithm to construct a Double Round Robin Tournament (DRRT) schedule with low travel cost. We then describe an enhanced genetic algorithm with a new crossover operator to improve the travel cost of the generated schedules. A new heuristic for ordering efficiently the scheduled rounds is also proposed. The latter leads to significant enhancement in the quality of the schedules. The overall method is evaluated on publicly available standard benchmarks and compared with other techniques for TTP and UTTP (Unconstrained Traveling Tournament Problem). The computational experiment shows that the proposed approach could build very good solutions comparable to other state-of-the-art approaches or better than the current best solutions on UTTP. Further, our method provides new valuable solutions to some unsolved UTTP instances and outperforms prior methods for all US National League (NL) instances.


1978 ◽  
Vol 26 (3) ◽  
pp. 422-426 ◽  
Author(s):  
H.N. Rutt ◽  
J.M. Green

2007 ◽  
Vol 112 (2) ◽  
pp. 467-472
Author(s):  
H. Teisseyre ◽  
M. Szymański ◽  
A. Khachapuridze ◽  
C. Skierbiszewski ◽  
A. Feduniewicz-Żmuda ◽  
...  

1977 ◽  
Vol 13 (9) ◽  
pp. 730-731 ◽  
Author(s):  
D. Dangoisse ◽  
A. Deldalle ◽  
J. Splingard ◽  
J. Bellet

1982 ◽  
Vol 18 (2) ◽  
pp. 62 ◽  
Author(s):  
H. Asahi ◽  
Y. Kawamura ◽  
H. Nagai ◽  
T. Ikegami

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