tailieunhanh - Báo cáo hóa học: " Phosphor-Free Apple-White LEDs with Embedded Indium-Rich Nanostructures Grown on Strain Relaxed Nano-epitaxy GaN"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Phosphor-Free Apple-White LEDs with Embedded Indium-Rich Nanostructures Grown on Strain Relaxed Nano-epitaxy GaN | Nanoscale Res Lett 2010 5 1788-1794 DOI s11671-010-9712-0 NANO EXPRESS Phosphor-Free Apple-White LEDs with Embedded Indium-Rich Nanostructures Grown on Strain Relaxed Nano-epitaxy GaN C. B. Soh W. Liu A. M. Yong S. J. Chua S. Y. Chow S. Tripathy R. J. N. Tan Received 28 June 2010 Accepted 19 July 2010 Published online 1 August 2010 The Author s 2010. This article is published with open access at Abstract Phosphor-free apple-white light emitting diodes have been fabricated using a dual stacked InGaN GaN multiple quantum wells comprising of a lower set of long wavelength emitting indium-rich nanostructures incorporated in multiple quantum wells with an upper set of cyan-green emitting multiple quantum wells. The lightemitting diodes were grown on nano-epitaxially lateral overgrown GaN template formed by regrowth of GaN over SiO2 film patterned with an anodic aluminum oxide mask with holes of 125 nm diameter and a period of 250 nm. The growth of InGaN GaN multiple quantum wells on these stress relaxed low defect density templates improves the internal quantum efficiency by 15 for the cyan-green multiple quantum wells. Higher emission intensity with redshift in the PL peak emission wavelength is obtained for the indium-rich nanostructures incorporated in multiple quantum wells. The quantum wells grown on the nano-epitaxially lateral overgrown GaN has a weaker piezoelectric field and hence shows a minimal peak shift with application of higher injection current. An enhancement of external quantum efficiency is achieved for the apple-white light emitting diodes grown on the nano-epitaxially lateral overgrown GaN template based on the light -output power C. B. Soh W. Liu A. M. Yong S. J. Chua S. Y. Chow S. Tripathy R. J. N. Tan Institute of Materials Research and Engineering A STAR Agency for Science Technology and Research 3 Research Link Singapore 117602 Singapore e-mail cb-soh@ S. J. Chua e-mail elecsj@ S. J. Chua .