Wurtzite strcture gallium nitride, GaN,a direct bandgap semiconductor (3.4 eV at room temperature),is an ideal material for fabrication of blue/green light emit ti ng diodes, laser diodes,and high power integrated cir...Wurtzite strcture gallium nitride, GaN,a direct bandgap semiconductor (3.4 eV at room temperature),is an ideal material for fabrication of blue/green light emit ti ng diodes, laser diodes,and high power integrated circuits.Recent progress in th in film crystal technique has realized the output of blue semiconductor lasers w i th a lifetime of over 10000 hours under continuous wave operation at room tempe r ature.So far GaN and its ternary indium and aluminum alloys are grown almost uni v ersally on foreign substrates with varying lattice mismatches.The mismatch undou btedly results in a significant dislocation density in the grown films.Hence it is necessary to grow single crystal GaN to be used as substrates for improvement of laser diodes.On the other hand,low dimensional GaN materials such as nanocry stalline powder,nanocrystal assembled bulk(nanophase) and nano wires are very u seful in both fundamental mesoscopic research and future development of GaN nano devices.Here we report our main recent progresses on the crystal growth of GaN a nd the preparation of its low dimensional materials.展开更多
While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdl...While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdle,we successfully prepared a functional and stable porphyrinic metal-organic framework(MOF),PCN-224-RT,as a host for encapsulating metal nanoparticles by direct stirring at room temperature.As a result,Pt@PCN-224-RT composites with well-dispersed Pt NPs can be constructed by introducing pre-synthesized Pt NPs into the precursor solution of PCN-224-RT.Of note,the rapid and simple stirring method in this work is more in line with the requirements of environmental friendly and industrialization compared with traditional solvothermal methods.展开更多
文摘Wurtzite strcture gallium nitride, GaN,a direct bandgap semiconductor (3.4 eV at room temperature),is an ideal material for fabrication of blue/green light emit ti ng diodes, laser diodes,and high power integrated circuits.Recent progress in th in film crystal technique has realized the output of blue semiconductor lasers w i th a lifetime of over 10000 hours under continuous wave operation at room tempe r ature.So far GaN and its ternary indium and aluminum alloys are grown almost uni v ersally on foreign substrates with varying lattice mismatches.The mismatch undou btedly results in a significant dislocation density in the grown films.Hence it is necessary to grow single crystal GaN to be used as substrates for improvement of laser diodes.On the other hand,low dimensional GaN materials such as nanocry stalline powder,nanocrystal assembled bulk(nanophase) and nano wires are very u seful in both fundamental mesoscopic research and future development of GaN nano devices.Here we report our main recent progresses on the crystal growth of GaN a nd the preparation of its low dimensional materials.
基金the National Natural Science Foundation of China(Nos.21701187,21701160)Natural Science Basic Research Program of Shaanxi(No.2020JQ-142)the Fundamental Research Funds for the Central Universities(No.31020180QD115).
文摘While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdle,we successfully prepared a functional and stable porphyrinic metal-organic framework(MOF),PCN-224-RT,as a host for encapsulating metal nanoparticles by direct stirring at room temperature.As a result,Pt@PCN-224-RT composites with well-dispersed Pt NPs can be constructed by introducing pre-synthesized Pt NPs into the precursor solution of PCN-224-RT.Of note,the rapid and simple stirring method in this work is more in line with the requirements of environmental friendly and industrialization compared with traditional solvothermal methods.
