GaN-based micro light emitting diodes(micro-LEDs) on silicon(Si)substrates with 40μm in diameter are developed utilizing standard photolithography and inductively coupled plasma etching techniques.From currentvoltage...GaN-based micro light emitting diodes(micro-LEDs) on silicon(Si)substrates with 40μm in diameter are developed utilizing standard photolithography and inductively coupled plasma etching techniques.From currentvoltage curves,the relatively low turn-on voltage of 2.8 V and low reverse leakage current in the order of 10-8 A/cm2 indicate good electrical characteristics.As the injection current increases,the electroluminescence emission wavelength hardly shifts at around 433 nm, and the relative external quantum efficiency slightly decays,because the impact of quantum-confined Stark effect is not serious in violet-blue micro-LEDs.Since GaN-LEDs are cost effective on large-area Si and suitable for substrate transfer or vertical device structures,the fabricated micro-LEDs on Si should have promising applications in the fields of high-resolution display and optical communication.展开更多
A significant enhancement in solar hydrogen generation efficiency has been achieved by inductive coupled etching （ICP） surface roughening treatment using nano-sized nickel mask. As much as 7 times improvement of pho...A significant enhancement in solar hydrogen generation efficiency has been achieved by inductive coupled etching （ICP） surface roughening treatment using nano-sized nickel mask. As much as 7 times improvement of photocurrent is demonstrated in comparison with a planar one fabricated from the same parent wafer. Under identical illumination conditions in HBr solution, the incident photon conversion efficiency （IPCE） shows an enhancement with a factor of 3, which even exceed 54% at 400 nm wavelength. We believe the enhancement is attributed to several facts including improvement in absorption, reacting area, carder localization and carrier lifetime.展开更多
InGaN layers capped with GaN were annealed at 550℃ for 1 hour. During annealing, cracks appeared and dissolved In GaN penetrated through the microcracks into the V-pits to form indium-rich nanoprecipitates. Some prec...InGaN layers capped with GaN were annealed at 550℃ for 1 hour. During annealing, cracks appeared and dissolved In GaN penetrated through the microcracks into the V-pits to form indium-rich nanoprecipitates. Some precipitates, in-situ annealed under nitrogen ion irradiation by MBE, were confirmed to be cubic GaN on the tops of precipitates, formed by nitriding the pre-existing Ga droplets under nitrogen ions irradiation.展开更多
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFB0400100the National Natural Science Foundation of China under Grant Nos 61674076,61674081 and 61605071+4 种基金the Natural Science Foundation of Jiangsu Province under Grant Nos BY2013077,BK20141320 and BE2015111the Six Talent Peaks Project of Jiangsu Province under Grant No XYDXX-081the Open Fund of the State Key Laboratory on Integrated Optoelectronics under Grant No IOSKL2017KF03the Fundamental Research Funds for the Central Universitiesthe Collaborative Innovation Center of Solid State Lighting and Energy-Saving Electronics
文摘GaN-based micro light emitting diodes(micro-LEDs) on silicon(Si)substrates with 40μm in diameter are developed utilizing standard photolithography and inductively coupled plasma etching techniques.From currentvoltage curves,the relatively low turn-on voltage of 2.8 V and low reverse leakage current in the order of 10-8 A/cm2 indicate good electrical characteristics.As the injection current increases,the electroluminescence emission wavelength hardly shifts at around 433 nm, and the relative external quantum efficiency slightly decays,because the impact of quantum-confined Stark effect is not serious in violet-blue micro-LEDs.Since GaN-LEDs are cost effective on large-area Si and suitable for substrate transfer or vertical device structures,the fabricated micro-LEDs on Si should have promising applications in the fields of high-resolution display and optical communication.
基金supported by the Special Funds for Major State Basic Research Project of China(Grant Nos.2011CB301900,2012CB619304,and 2010CB327504)the Hi-tech Research Project of China(Grant No.2011AA03A103)+4 种基金the National Nature Science Foundation of China(Grant Nos.60990311,61274003,60936004,and 61176063)the Program for New Century Excellent Talents in University of China(Grant No.NCET-11-0229)the Natural Science Foundation of Jiangsu Province of China(Grant No.BK2011010)the Funds of Key Laboratory of China(Grant No.9140C140102120C14)the Research Funds from NJU-Yangzhou Institute of Opto-electronics of China
文摘A significant enhancement in solar hydrogen generation efficiency has been achieved by inductive coupled etching （ICP） surface roughening treatment using nano-sized nickel mask. As much as 7 times improvement of photocurrent is demonstrated in comparison with a planar one fabricated from the same parent wafer. Under identical illumination conditions in HBr solution, the incident photon conversion efficiency （IPCE） shows an enhancement with a factor of 3, which even exceed 54% at 400 nm wavelength. We believe the enhancement is attributed to several facts including improvement in absorption, reacting area, carder localization and carrier lifetime.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61604080,61574079,61634002,and 61474060)Natural Science Foundation of Jiangsu Province,China(Grant No.BK20160883)+1 种基金University Science Research Project of Jiangsu Province,China(Grant Nos.16KJB140011 and14KJB510020)NUPTSF,China(Grant No.NY214154)
文摘InGaN layers capped with GaN were annealed at 550℃ for 1 hour. During annealing, cracks appeared and dissolved In GaN penetrated through the microcracks into the V-pits to form indium-rich nanoprecipitates. Some precipitates, in-situ annealed under nitrogen ion irradiation by MBE, were confirmed to be cubic GaN on the tops of precipitates, formed by nitriding the pre-existing Ga droplets under nitrogen ions irradiation.
