To develop porous Si as substrate for better quality GaN layer
In this work, we prepare porous Si substrates via anodic etching process. The etching parameters such as time and current would be optimized for the best porous substrate, which is defined by having high porous density. The estimated average of porous density of the substrate is determined through the observation via scanning electron microscopy (SEM). After that, a thin GaN film is deposited onto the best porous Si substrate, using RF-sputtering machine. The grown layer is then will be characterized by photoluminescence (PL), X-ray diffraction (XRD) and Hall-effect measurements. As a comparison, we also grow and characterize a thin GaN on non-porous Si substrate, with the adoption of AlN buffer layer.
Growth of InGaN/GaN multiple-quantum-well blue light-emitting diodes on silicon by metalorganic vapor phase epitaxy
We report the growth of InGaN/GaN multiple-quantum-well blue light-emitting diode (LED) structures on Si(111) using metalorganic vapor phase epitaxy. By using growth conditions optimized for sapphire substrates, a full width at half maximum (FWHM) (102) x-ray rocking curve of less than 600 arcsec and a room-temperature photoluminescence peak at 465 nm with a FWHM of 35 nm was obtained. Simple LEDs emitting bright electroluminescence between 450 and 480 nm with turn-on voltages at 5 V were demonstrated.
The lights that failed: European international history, 1919-1933
PART I: THE RECONSTRUCTION OF EUROPE, 1918-1929 1. The Hall of Mirrors: Peacemaking in the West 2. Distant Frontiers: Peacemaking in the East 3. Revolution from the Left: The Soviet Union and the Post-War Settlement 4. The Primacy of Economics: Reconstruction in Western Europe, 1919-1924 5. The Primacy of Nationalism: Reconstruction in Eastern and Central Europe 6. Revolution from the Right: Italy, 1919-25 7. The Geneva Dream: The League of Nations and Post-War Internationalism 8. New Dawn? Stabilisation in Western Europe after Locarno 9. Faltering Reconstruction: Cracks in the Locarno Facade 10. Troubled Waters: Uncertainties in Italy, Eastern Europe and the Soviet Union 11. Faltering Internationalism: Disarmament and Security after Locarno Conclusion: Europe Reconstructed? PART II: THE HINGE YEARS, 1930-1933 12. The Diplomacy of the Depression: Economics and Foreign Policy 13. Beyond Europe: The Manchurian Crisis 14. The Poisoned Chalice: The Pursuit of Disarmament Conclusion: The Hinge Years Appendices Select Bibliography