Waveguide characteristics of symmetrical separate confinement heterojunction multi quantum well (SCH MQW) AlGaN/GaN/InGaN laser diode (LD) are studied by using one dimensional (1 D) transfer matrix waveguide appro...Waveguide characteristics of symmetrical separate confinement heterojunction multi quantum well (SCH MQW) AlGaN/GaN/InGaN laser diode (LD) are studied by using one dimensional (1 D) transfer matrix waveguide approach.Aiming at photon confinement factor,threshold current,and power efficiency,layers design for SCH MQW LD is optimized.The optimal layers parameters are 3 periods In 0.02 Ga 0.98 N/In 0.15 Ga 0.85 N QW for active layer,In 0.1 Ga 0 9 N for waveguide layer with 90nm thick,and 120×(2 5nm/2 5nm) Al 0.25 Ga 0 75 N/GaN supper lattices for cladding layer with the laser wavelength of 396 6nm.展开更多
The upper waveguide （UWG） has direct influences on the optical and electrical characteristics of the violet laser diode （LD） by changing the optical field distribution or barrier of the electron blocking layer （...The upper waveguide （UWG） has direct influences on the optical and electrical characteristics of the violet laser diode （LD） by changing the optical field distribution or barrier of the electron blocking layer （EBL）. In this study, a series of InGaN-based violet LDs with different UWGs are investigated systematically with LASTIP software. It is found that the output light power （OLP） under an injecting current of 120 mA or the threshold current （Ith） is deteriorated when the UWG is u-In0.02Ga0.98N/GaN or u-In0.02Ga0.98N/AlxGa1-xN （0 ≤ x ≤ 0.1）, which should be attributed to small optical confinement factor （OCF） or severe electron leakage. Therefore, a new violet LD structure with u-In0.02Ga0.98N/GaN/Al0.05Ga0.95N multiple layer UWG is proposed to reduce the optical loss and increase the barrier of EBL. Finally, the output light power under an injecting current of 120 mA is improved to 176.4 mW.展开更多
Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically,...Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.展开更多
文摘Waveguide characteristics of symmetrical separate confinement heterojunction multi quantum well (SCH MQW) AlGaN/GaN/InGaN laser diode (LD) are studied by using one dimensional (1 D) transfer matrix waveguide approach.Aiming at photon confinement factor,threshold current,and power efficiency,layers design for SCH MQW LD is optimized.The optimal layers parameters are 3 periods In 0.02 Ga 0.98 N/In 0.15 Ga 0.85 N QW for active layer,In 0.1 Ga 0 9 N for waveguide layer with 90nm thick,and 120×(2 5nm/2 5nm) Al 0.25 Ga 0 75 N/GaN supper lattices for cladding layer with the laser wavelength of 396 6nm.
基金Project supported by the National Key R&D Program of China(Grant Nos.2016YFB0400803 and 2016YFB0401801)the National Natural Science Foundation of China(Grant Nos.61674138,61674139,61604145,61574135,61574134,61474142,61474110,61377020,and 61376089)+1 种基金the Science Challenge Project,China(Grant No.TZ2016003)the Beijing Municipal Science and Technology Project,China(Grant No.Z161100002116037)
文摘The upper waveguide （UWG） has direct influences on the optical and electrical characteristics of the violet laser diode （LD） by changing the optical field distribution or barrier of the electron blocking layer （EBL）. In this study, a series of InGaN-based violet LDs with different UWGs are investigated systematically with LASTIP software. It is found that the output light power （OLP） under an injecting current of 120 mA or the threshold current （Ith） is deteriorated when the UWG is u-In0.02Ga0.98N/GaN or u-In0.02Ga0.98N/AlxGa1-xN （0 ≤ x ≤ 0.1）, which should be attributed to small optical confinement factor （OCF） or severe electron leakage. Therefore, a new violet LD structure with u-In0.02Ga0.98N/GaN/Al0.05Ga0.95N multiple layer UWG is proposed to reduce the optical loss and increase the barrier of EBL. Finally, the output light power under an injecting current of 120 mA is improved to 176.4 mW.
基金supported by the National Natural Science Foundation of China(Grant No.61176043)the Special Funds for Provincial Strategic and Emerging Industries Projects of Guangdong Province,China(Grant Nos.2010A081002005,2011A081301003,and 2012A080304016)the Youth Foundation of South China Normal University(Grant No.2012KJ018)
文摘Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.
