摘要
Current laser-based display and lighting applications are invariably using blue laser diodes(LDs)grown on freestanding GaN substrates,which are costly and smaller in size compared with other substrate materials.1–3 Utilizing less expensive and large-diameter Si substrates for hetero-epitaxial growth of indium gallium nitride/gallium nitride(InGaN/GaN)multiple quantum well(MQW)structure can substantially reduce the cost of blue LDs and boost their applications.To obtain a high crystalline quality crack-free GaN thin film on Si for the subsequent growth of a blue laser structure,a hand-shaking structure was formed by inserting Al-composition step down-graded AlN/AlxGa1−xN buffer layers between GaN and Si substrate.Thermal degradation in InGaN/GaN blue MQWs was successfully suppressed with indium-rich clusters eliminated by introducing hydrogen during the growth of GaN quantum barriers(QBs)and lowering the growth temperature for the p-type AlGaN/GaN superlattice optical cladding layer.A continuous-wave(CW)electrically pumped InGaN/GaN quantum well(QW)blue(450 nm)LD grown on Si was successfully demonstrated at room temperature(RT)with a threshold current density of 7.8 kA/cm^(2).
基金
support from the National Key R&D Program(Grant No.2016YFB0400100,2016YFB0400104)
the National Natural Science Foundation of China(Grant Nos.61534007,61404156,61522407,61604168,and 61775230)
the Key Frontier Scientific Research Program of the Chinese Academy of Sciences(Grant No.QYZDB-SSWJSC014)
the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA09020401)
the Science and Technology Service Network Initiative of the Chinese Academy of Sciences
the Key R&D Program of Jiangsu Province(Grant No.BE2017079)
the Natural Science Foundation of Jiangsu Province(Grant No.BK20160401)
supported by the open fund of the State Key Laboratory of Luminescence and Applications(Grant No.SKLA-2016-01)
the open fund of the State Key Laboratory on Integrated Optoelectronics(Grant No.IOSKL2016KF04,and IOSKL2016KF07).
