Investigating closely stacked GaN/AlN multiple quantum wells(MQWs)by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope,we have reached an ultimate spatial reso...Investigating closely stacked GaN/AlN multiple quantum wells(MQWs)by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope,we have reached an ultimate spatial resolution ofσCL=1.8 nm.The pseudomorphically grown MQWs with high interface quality emit in the deep ultraviolet spectral range.Demonstrating the capability of resolving the 10.8 nm separated,ultra-thin quantum wells,a cathodoluminescence profile was taken across individual ones.Applying a diffusion model of excitons generated by a Gaussian-broadened electron probe,the spatial resolution of cathodoluminescence down to the free exciton Bohr radius scale has been determined.展开更多
Through insertion of an AlGaN/GaN stack between the u-GaN and n-GaN of GaN-based light-emitting diodes （LEDs）, the strain in the epilayer was increased, the dislocation density was reduced. GaN-based LEDs with diffe...Through insertion of an AlGaN/GaN stack between the u-GaN and n-GaN of GaN-based light-emitting diodes （LEDs）, the strain in the epilayer was increased, the dislocation density was reduced. GaN-based LEDs with different Al compositions were compared. 6.8% Al composition in the stacks showed the highest electrostatic discharge （ESD） endurance ability at the human body mode up to 6000 V and the pass yield exceeded 95%.展开更多
We present high-performance enhancement-mode AlGaN/GaN metal-oxide-semiconductor highelectron mobility transistors（MOS-HEMTs） by a fluorinated gate dielectric technique.A nanolaminate of an Al_2O_3/La_xAl_（1-x）O_3...We present high-performance enhancement-mode AlGaN/GaN metal-oxide-semiconductor highelectron mobility transistors（MOS-HEMTs） by a fluorinated gate dielectric technique.A nanolaminate of an Al_2O_3/La_xAl_（1-x）O_3/Al_2O_3 stack（x≈0.33） grown by atomic layer deposition is employed to avoid fluorine ions implantation into the scaled barrier layer.Fabricated enhancement-mode MOS-HEMTs exhibit an excellent performance as compared to those with the conventional dielectric-last technique,delivering a large maximum drain current of 916 mA/mm and simultaneously a high peak transconductance of 342 mS/mm.The balanced DC characteristics indicate that advanced gate stack dielectrics combined with buffered fluorine ions implantation have a great potential for high speed GaN E/D-mode integrated circuit applications.展开更多
基金National Key Research and Development Program of China(2017YFE0100300)Science Challenge Project(TZ2016003)+1 种基金National Natural Science Foundation of China(61734001,61521004,61774004)Deutsche Forschungsgemeinschaft(Research Instrumentation Program INST272/148-1,Collaborative Research Center SFB 787)。
文摘Investigating closely stacked GaN/AlN multiple quantum wells(MQWs)by means of cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope,we have reached an ultimate spatial resolution ofσCL=1.8 nm.The pseudomorphically grown MQWs with high interface quality emit in the deep ultraviolet spectral range.Demonstrating the capability of resolving the 10.8 nm separated,ultra-thin quantum wells,a cathodoluminescence profile was taken across individual ones.Applying a diffusion model of excitons generated by a Gaussian-broadened electron probe,the spatial resolution of cathodoluminescence down to the free exciton Bohr radius scale has been determined.
基金supported by the National High Technology Research and Development Program of China(No.2008AA03A197)
文摘Through insertion of an AlGaN/GaN stack between the u-GaN and n-GaN of GaN-based light-emitting diodes （LEDs）, the strain in the epilayer was increased, the dislocation density was reduced. GaN-based LEDs with different Al compositions were compared. 6.8% Al composition in the stacks showed the highest electrostatic discharge （ESD） endurance ability at the human body mode up to 6000 V and the pass yield exceeded 95%.
基金supported by the National Natural Science Foundation of China(Nos.61504125,61474101,61106130 61076120,61505181)the Natural Science Foundation of Jiangsu Province of China(Nos.BK20131072,BE2012007,BK2012516)
文摘We present high-performance enhancement-mode AlGaN/GaN metal-oxide-semiconductor highelectron mobility transistors（MOS-HEMTs） by a fluorinated gate dielectric technique.A nanolaminate of an Al_2O_3/La_xAl_（1-x）O_3/Al_2O_3 stack（x≈0.33） grown by atomic layer deposition is employed to avoid fluorine ions implantation into the scaled barrier layer.Fabricated enhancement-mode MOS-HEMTs exhibit an excellent performance as compared to those with the conventional dielectric-last technique,delivering a large maximum drain current of 916 mA/mm and simultaneously a high peak transconductance of 342 mS/mm.The balanced DC characteristics indicate that advanced gate stack dielectrics combined with buffered fluorine ions implantation have a great potential for high speed GaN E/D-mode integrated circuit applications.
