The Experts below are selected from a list of 453285 Experts worldwide ranked by ideXlab platform
Kenichi Kasahara - One of the best experts on this subject based on the ideXlab platform.
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Temperature Characteristics of a vertical-cavity surface-emitting laser with a broad-gain bandwidth
IEEE Journal of Selected Topics in Quantum Electronics, 1995Co-Authors: M. Kajita, T. Kawakami, M. Nido, A. Kimura, Takashi Yoshikawa, Kaori Kurihara, Yoshimasa Sugimoto, Kenichi KasaharaAbstract:Temperature-insensitive Characteristics are of great importance in implementing the actual applications of vertical-cavity surface-emitting lasers (VCSEL's) because of the Temperature change in the surroundings. To extend the operational Temperature range of such lasers, we fabricated a VCSEL with a broad gain bandwidth. The active layers in VCSEL's consist of multiple quantum wells (MQW's) with different bandgap energies. From the change in the threshold current, with Temperature as a parameter, we found that the operational Temperature range of a VCSEL with a broad gain bandwidth is more than 20/spl deg/C wider than that of conventional VCSEL's, whose active layers consist of a single type of MQW. We demonstrate that the extended-gain bandwidth gives better Temperature Characteristics. In addition, we simulated the structure of the active layers, and the optimized structure resulted in a 1-mW light output power at less than 5 mA in a single transverse mode oscillation from 20-70/spl deg/C. >
Kensuke Nishioka - One of the best experts on this subject based on the ideXlab platform.
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detailed analysis of Temperature Characteristics of an ingap ingaas ge triple junction solar cell
Journal of Electronic Materials, 2010Co-Authors: Kensuke Nishioka, Tsuyoshi Sueto, Masaki Uchida, Yasuyuki OtaAbstract:Temperature Characteristics of an InGaP/InGaAs/Ge triple-junction solar cell were analyzed in detail using an equivalent circuit calculation. The current–voltage (I–V) Characteristics of single-junction solar cells (InGaP, InGaAs, Ge solar cells) were measured at various Temperatures. Fitting of I–V curves between measured and calculated data was carried out, and the diode parameters and Temperature exponents of the single-junction solar cells were extracted. The parameters for each single-junction solar cell were used in the equivalent circuit model for the triple-junction solar cell, and calculations of solar cell performance were carried out. Measured and calculated results of the I–V Characteristics at various Temperatures agreed well.
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evaluation of Temperature Characteristics of high efficiency ingap ingaas ge triple junction solar cells under concentration
Solar Energy Materials and Solar Cells, 2005Co-Authors: Kensuke Nishioka, Tatsuya Takamoto, Takaaki Agui, M Kaneiwa, Yukiharu Uraoka, Takashi FuyukiAbstract:Abstract Temperature Characteristics of the open-circuit voltage (Voc) were investigated in the Temperature range from 30°C to 240°C for the InGaP/InGaAs/Ge triple-junction cells. Also, single-junction cells that had the similar structure to the subcells in the triple-junction cells were studied. In the high-Temperature range (from 170°C to 240°C), the Temperature coefficients of Voc of the InGaP/InGaAs/Ge triple-junction solar cell (dVoc/dT) were different from those in the low-Temperature range (from 30°C to 100°C). This is because photo-voltage from the Ge subcell becomes almost 0 V in the high-Temperature range. It was found that the open-circuit voltage of a Ge single-junction cell reduced to almost 0 V Temperatures over 120°C under 1 sun condition.
Takashi Fuyuki - One of the best experts on this subject based on the ideXlab platform.
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evaluation of Temperature Characteristics of high efficiency ingap ingaas ge triple junction solar cells under concentration
Solar Energy Materials and Solar Cells, 2005Co-Authors: Kensuke Nishioka, Tatsuya Takamoto, Takaaki Agui, M Kaneiwa, Yukiharu Uraoka, Takashi FuyukiAbstract:Abstract Temperature Characteristics of the open-circuit voltage (Voc) were investigated in the Temperature range from 30°C to 240°C for the InGaP/InGaAs/Ge triple-junction cells. Also, single-junction cells that had the similar structure to the subcells in the triple-junction cells were studied. In the high-Temperature range (from 170°C to 240°C), the Temperature coefficients of Voc of the InGaP/InGaAs/Ge triple-junction solar cell (dVoc/dT) were different from those in the low-Temperature range (from 30°C to 100°C). This is because photo-voltage from the Ge subcell becomes almost 0 V in the high-Temperature range. It was found that the open-circuit voltage of a Ge single-junction cell reduced to almost 0 V Temperatures over 120°C under 1 sun condition.
M. Kajita - One of the best experts on this subject based on the ideXlab platform.
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Temperature Characteristics of a vertical-cavity surface-emitting laser with a broad-gain bandwidth
IEEE Journal of Selected Topics in Quantum Electronics, 1995Co-Authors: M. Kajita, T. Kawakami, M. Nido, A. Kimura, Takashi Yoshikawa, Kaori Kurihara, Yoshimasa Sugimoto, Kenichi KasaharaAbstract:Temperature-insensitive Characteristics are of great importance in implementing the actual applications of vertical-cavity surface-emitting lasers (VCSEL's) because of the Temperature change in the surroundings. To extend the operational Temperature range of such lasers, we fabricated a VCSEL with a broad gain bandwidth. The active layers in VCSEL's consist of multiple quantum wells (MQW's) with different bandgap energies. From the change in the threshold current, with Temperature as a parameter, we found that the operational Temperature range of a VCSEL with a broad gain bandwidth is more than 20/spl deg/C wider than that of conventional VCSEL's, whose active layers consist of a single type of MQW. We demonstrate that the extended-gain bandwidth gives better Temperature Characteristics. In addition, we simulated the structure of the active layers, and the optimized structure resulted in a 1-mW light output power at less than 5 mA in a single transverse mode oscillation from 20-70/spl deg/C. >
Kaori Kurihara - One of the best experts on this subject based on the ideXlab platform.
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Temperature Characteristics of a vertical-cavity surface-emitting laser with a broad-gain bandwidth
IEEE Journal of Selected Topics in Quantum Electronics, 1995Co-Authors: M. Kajita, T. Kawakami, M. Nido, A. Kimura, Takashi Yoshikawa, Kaori Kurihara, Yoshimasa Sugimoto, Kenichi KasaharaAbstract:Temperature-insensitive Characteristics are of great importance in implementing the actual applications of vertical-cavity surface-emitting lasers (VCSEL's) because of the Temperature change in the surroundings. To extend the operational Temperature range of such lasers, we fabricated a VCSEL with a broad gain bandwidth. The active layers in VCSEL's consist of multiple quantum wells (MQW's) with different bandgap energies. From the change in the threshold current, with Temperature as a parameter, we found that the operational Temperature range of a VCSEL with a broad gain bandwidth is more than 20/spl deg/C wider than that of conventional VCSEL's, whose active layers consist of a single type of MQW. We demonstrate that the extended-gain bandwidth gives better Temperature Characteristics. In addition, we simulated the structure of the active layers, and the optimized structure resulted in a 1-mW light output power at less than 5 mA in a single transverse mode oscillation from 20-70/spl deg/C. >
