The Experts below are selected from a list of 80298 Experts worldwide ranked by ideXlab platform
W C Lai - One of the best experts on this subject based on the ideXlab platform.
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high speed gan based green light emitting diodes with partially n doped active layers and current confined apertures
IEEE Electron Device Letters, 2008Co-Authors: Jinwei Shi, Jinnkong Sheu, C H Chen, Gongru Lin, W C LaiAbstract:We demonstrate a high-speed GaN-based green light-emitting diode for plastic optical fiber (POF) communication applications. By using a combination of N-Type Doping and undoped InxGa1-xN/GaN based multiple quantum wells (MQWs), and a 76-mum-diameter current-confined aperture structure, we can obtain an extremely high electrical-to-optical (E-O) 3 dB bandwidth (~330 MHz), which is limited by the spontaneous recombination lifetime of the MQWs. A reasonable coupled power (-264 muW) can be simultaneously achieved for a 2 mm in diameter POF with a 0.5 numerical aperture (NA).
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the improvement in modulation speed of gan based green light emitting diode led by use of n type barrier Doping for plastic optical fiber pof communication
IEEE Photonics Technology Letters, 2006Co-Authors: H Y Huang, Jinnkong Sheu, C H Chen, Y S Wu, W C LaiAbstract:We demonstrate a high-speed GaN-based light-emitting diode at a wavelength of around 500 nm for the application to plastic optical fiber communication. By use of the N-Type Doping in the GaN barrier layers of the InxGa1-xN-GaN-based multiple-quantum-well (MQW), superior performance of modulation-speed (120 versus 40 MHz) and output power to the undoped control under the same bias current has been observed. According to the measured electrical-to-optical bandwidths and extracted RC-limited bandwidths of both devices, the superior speed performance can be attributed to higher electron/hole radiative recombination rate in the n-doped MQW than that of undoped MQW
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modulation speed enhancement of a gan based green light emitting diode led by use of n type barrier Doping for plastic optical fiber pof communication
Quantum Electronics and Laser Science Conference, 2006Co-Authors: H Y Huang, Jinnkong Sheu, Gongru Lin, W C Lai, J I Chyi, Y S Wu, Ciling PanAbstract:We demonstrate a high-speed green GaN light-emitting-diode for plastic optical fiber communication. By use of N-Type Doping in barrier layers, superior performance of modulation-speed and output-power to undoped control has been observed.
Wilhelm Warta - One of the best experts on this subject based on the ideXlab platform.
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high efficiency multicrystalline silicon solar cells potential of n type Doping
IEEE Journal of Photovoltaics, 2015Co-Authors: Florian Schindler, Jonas Schon, B Michl, Stephan Riepe, Patricia Krenckel, Jan Benick, Frank Feldmann, Martin Hermle, S W Glunz, Wilhelm WartaAbstract:In this study, we demonstrate the potential of multicrystalline (mc) N-Type silicon for the fabrication of highly efficient mc-Si solar cells. High-quality mc N-Type silicon wafers are obtained from a research ingot crystallized in a high-purity crucible, using high-purity granular silicon as seed layer in the crucible bottom and high-purity polysilicon feedstock for the block. An mc p-type silicon block crystallized under identical conditions (same seed and feedstock, crucible system, and temperature profiles) serves as reference and enables measurements of the interstitial iron and chromium concentrations by metastable defect imaging. In combination with 2-D simulations for in-diffusion and precipitation of chromium, the limitation of N-Type high-performance mc silicon by these metals is assessed after different solar cell processing steps. Material-related efficiency losses are assessed by an “efficiency limiting bulk recombination analysis,” which combines injection-dependent photoluminescence imaging of minority charge carrier diffusion length with PC1D cell simulations. Finally, based on this material, boron-diffused front-junction mc N-Type silicon solar cells with a full-area passivated rear contact (TOPCon) are fabricated. The record cell features an efficiency of 19.6%, which is the highest efficiency reported for an mc N-Type silicon solar cell.
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high efficiency multicrystalline silicon solar cells potential of n type Doping
Photovoltaic Specialists Conference, 2015Co-Authors: Florian Schindler, Jonas Schon, B Michl, Stephan Riepe, Patricia Krenckel, Jan Benick, Frank Feldmann, Martin Hermle, S W Glunz, Wilhelm WartaAbstract:By quantifying the role of dopants, impurities and crystal structure, we present guidelines for the fabrication of highly efficient multicrystalline (mc) silicon solar cells. Processed mc N-Type wafers feature higher charge carrier diffusion lengths and thus a significantly larger efficiency potential compared with identically produced mc p-type wafers. Still, metal impurities limit the charge carrier lifetime in mc N-Type wafers. We identify the main metal impurities in mc N-Type silicon and quantify the resulting recombination losses. Attributing the main losses to precipitates and decorated crystal defects, the optimal efficiency potential of mc silicon is exploited by combining N-Type high-performance multicrystalline silicon (HPM-Si) with a high efficiency cell concept featuring a full area passivated rear contact (TOPCon). The record cell features an efficiency of 19.6%, which is the highest efficiency reported for an mc N-Type silicon solar cell. By reducing series resistance losses and improving the optics of the front surface, efficiencies of 21–22% should be attainable on N-Type HPM-Si TOPCon solar cells.
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potential gain in multicrystalline silicon solar cell efficiency by n type Doping
IEEE Journal of Photovoltaics, 2015Co-Authors: Florian Schindler, Jonas Schon, B Michl, Stephan Riepe, Patricia Krenckel, Wilhelm Warta, Andreas Kleiber, Heiko Steinkemper, Wolfram Kwapil, Martin C SchubertAbstract:This study aims for a quantitative investigation of the material limitations and the efficiency potential of an entire multicrystalline (mc) N-Type silicon block in comparison with an mc p-type block of the same purity level in order to predict the potential of mc N-Type silicon for the industrial production of solar cells. Therefore, two standard mc silicon blocks were crystallized under identical conditions (same high purity feedstock, crucible system, and temperature profiles), only differing in their type of Doping. The material quality of wafers along the whole block height is analyzed after different solar cell process steps by photoluminescence imaging of the diffusion length. The bulk recombination related efficiency losses are assessed by an “efficiency limiting bulk recombination analysis (ELBA),” combining injection dependent lifetime images with PC1D cell simulations. The influence of the base resistivity variation along the block is considered in the PC1D cell simulations and backed up by Sentaurus Device simulations. This analysis predicts a significantly higher material-related efficiency potential after typical solar cell processes along the whole block height for mc N-Type silicon compared with mc p-type silicon. In addition, the efficiency potential for mc N-Type silicon depends less on block position.
Florian Schindler - One of the best experts on this subject based on the ideXlab platform.
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high efficiency multicrystalline silicon solar cells potential of n type Doping
IEEE Journal of Photovoltaics, 2015Co-Authors: Florian Schindler, Jonas Schon, B Michl, Stephan Riepe, Patricia Krenckel, Jan Benick, Frank Feldmann, Martin Hermle, S W Glunz, Wilhelm WartaAbstract:In this study, we demonstrate the potential of multicrystalline (mc) N-Type silicon for the fabrication of highly efficient mc-Si solar cells. High-quality mc N-Type silicon wafers are obtained from a research ingot crystallized in a high-purity crucible, using high-purity granular silicon as seed layer in the crucible bottom and high-purity polysilicon feedstock for the block. An mc p-type silicon block crystallized under identical conditions (same seed and feedstock, crucible system, and temperature profiles) serves as reference and enables measurements of the interstitial iron and chromium concentrations by metastable defect imaging. In combination with 2-D simulations for in-diffusion and precipitation of chromium, the limitation of N-Type high-performance mc silicon by these metals is assessed after different solar cell processing steps. Material-related efficiency losses are assessed by an “efficiency limiting bulk recombination analysis,” which combines injection-dependent photoluminescence imaging of minority charge carrier diffusion length with PC1D cell simulations. Finally, based on this material, boron-diffused front-junction mc N-Type silicon solar cells with a full-area passivated rear contact (TOPCon) are fabricated. The record cell features an efficiency of 19.6%, which is the highest efficiency reported for an mc N-Type silicon solar cell.
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high efficiency multicrystalline silicon solar cells potential of n type Doping
Photovoltaic Specialists Conference, 2015Co-Authors: Florian Schindler, Jonas Schon, B Michl, Stephan Riepe, Patricia Krenckel, Jan Benick, Frank Feldmann, Martin Hermle, S W Glunz, Wilhelm WartaAbstract:By quantifying the role of dopants, impurities and crystal structure, we present guidelines for the fabrication of highly efficient multicrystalline (mc) silicon solar cells. Processed mc N-Type wafers feature higher charge carrier diffusion lengths and thus a significantly larger efficiency potential compared with identically produced mc p-type wafers. Still, metal impurities limit the charge carrier lifetime in mc N-Type wafers. We identify the main metal impurities in mc N-Type silicon and quantify the resulting recombination losses. Attributing the main losses to precipitates and decorated crystal defects, the optimal efficiency potential of mc silicon is exploited by combining N-Type high-performance multicrystalline silicon (HPM-Si) with a high efficiency cell concept featuring a full area passivated rear contact (TOPCon). The record cell features an efficiency of 19.6%, which is the highest efficiency reported for an mc N-Type silicon solar cell. By reducing series resistance losses and improving the optics of the front surface, efficiencies of 21–22% should be attainable on N-Type HPM-Si TOPCon solar cells.
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potential gain in multicrystalline silicon solar cell efficiency by n type Doping
IEEE Journal of Photovoltaics, 2015Co-Authors: Florian Schindler, Jonas Schon, B Michl, Stephan Riepe, Patricia Krenckel, Wilhelm Warta, Andreas Kleiber, Heiko Steinkemper, Wolfram Kwapil, Martin C SchubertAbstract:This study aims for a quantitative investigation of the material limitations and the efficiency potential of an entire multicrystalline (mc) N-Type silicon block in comparison with an mc p-type block of the same purity level in order to predict the potential of mc N-Type silicon for the industrial production of solar cells. Therefore, two standard mc silicon blocks were crystallized under identical conditions (same high purity feedstock, crucible system, and temperature profiles), only differing in their type of Doping. The material quality of wafers along the whole block height is analyzed after different solar cell process steps by photoluminescence imaging of the diffusion length. The bulk recombination related efficiency losses are assessed by an “efficiency limiting bulk recombination analysis (ELBA),” combining injection dependent lifetime images with PC1D cell simulations. The influence of the base resistivity variation along the block is considered in the PC1D cell simulations and backed up by Sentaurus Device simulations. This analysis predicts a significantly higher material-related efficiency potential after typical solar cell processes along the whole block height for mc N-Type silicon compared with mc p-type silicon. In addition, the efficiency potential for mc N-Type silicon depends less on block position.
Jinhong Park - One of the best experts on this subject based on the ideXlab platform.
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stable and reversible triphenylphosphine based n type Doping technique for molybdenum disulfide mos2
ACS Applied Materials & Interfaces, 2018Co-Authors: Seohyeon Jo, Jaewoo Shim, Dongho Kang, Jinhong ParkAbstract:A highly stable and reversible N-Type Doping technique for molybdenum disulfide (MoS2) transistors and photodetectors is developed in this study. This Doping technique is based on triphenylphosphine (PPh3) and significantly improves the performance of MoS2 transistor and photodetector devices in terms of the on/off-current ratio (8.72 × 104 → 8.70 × 105), mobility (12.1 → 241 cm2/V·s), and photoresponsivity (R) (2.77 × 103 → 3.92 × 105 A/W). The range of Doping concentrations is broadly distributed between 1.56 × 1011 and 9.75 × 1012 cm–2 and is easily controlled by adjusting the temperature at which the PPh3 layer is formed. In addition, this Doping technique provides two interesting properties that have not been reported for previous molecular Doping techniques: (i) high stability leading to small variations in device performance after exposure to air for 14 days (on-current: 1.34% and photoresponsivity: 1.58%) and (ii) reversibility enabling the repetitive formation and removal of PPh3 molecules (dopin...
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nondegenerate n type Doping phenomenon on molybdenum disulfide mos2 by zinc oxide zno
Materials Research Bulletin, 2016Co-Authors: Dongho Kang, Seong Taek Hong, Aely Oh, Hyunyong Yu, Jinhong ParkAbstract:In this paper, we have demonstrated nondegenerate N-Type Doping phenomenon of MoS2 by ZnO. The ZnO Doping effects were systematically investigated by Raman spectroscopy and electrical/optical measurements (ID–VG with/without exposure to 520, 655, 785, and 850 nm laser sources). The ZnO Doping improved the performance parameters of MoS2-based electronics (Ion↑, μFE↑, n↑) owing to reduction of the effective barrier height between the source and the MoS2 channel. We also monitored the effects of ZnO Doping during exposure to air; reduction in ΔVTH of about 75% was observed after 156 h. In addition, the optoelectronic performance of the MoS2 photodetector was enhanced due to the reduction of the recombination rate of photogenerated carriers caused by ZnO Doping. In our results, the highest photoresponsivity (about 3.18 × 103 A/W) and detectivity (5.94 × 1012 Jones) of the ZnO-doped photodetector were observed for 520 nm laser exposure.
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controllable and air stable graphene n type Doping on phosphosilicate glass for intrinsic graphene
Organic Electronics, 2015Co-Authors: Hyungyoul Park, Jinsang Yoon, Jeaho Jeon, Jinok Kim, Sungjoo Lee, Jinhong ParkAbstract:Abstract We proposed and investigated a controllable air-stable graphene n-Doping method on phosphosilicate glass (PSG) to achieve intrinsic graphene. Through Raman, XPS, and AFM analyses, it was confirmed that the initially p-type doped graphene was recovered to intrinsic graphene through N-Type Doping phenomenon. The n-Doping control was accomplished by adjusting the concentration of the out-diffused P2O5 molecules from the PSG layer. In particular, a larger amount of P2O5 molecules and a smoother PSG surface were achieved after the higher temperature annealing, consequently yielding a larger Doping impact on the graphene layer. Finally, a very small Dirac point shift (1–3 V) was observed after 96 h of air exposure, compared to the degree of shift by the n-Doping effect (17–36 V), demonstrating that this n-Doping method is fairly stable in air.
Jinnkong Sheu - One of the best experts on this subject based on the ideXlab platform.
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high speed gan based green light emitting diodes with partially n doped active layers and current confined apertures
IEEE Electron Device Letters, 2008Co-Authors: Jinwei Shi, Jinnkong Sheu, C H Chen, Gongru Lin, W C LaiAbstract:We demonstrate a high-speed GaN-based green light-emitting diode for plastic optical fiber (POF) communication applications. By using a combination of N-Type Doping and undoped InxGa1-xN/GaN based multiple quantum wells (MQWs), and a 76-mum-diameter current-confined aperture structure, we can obtain an extremely high electrical-to-optical (E-O) 3 dB bandwidth (~330 MHz), which is limited by the spontaneous recombination lifetime of the MQWs. A reasonable coupled power (-264 muW) can be simultaneously achieved for a 2 mm in diameter POF with a 0.5 numerical aperture (NA).
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the improvement in modulation speed of gan based green light emitting diode led by use of n type barrier Doping for plastic optical fiber pof communication
IEEE Photonics Technology Letters, 2006Co-Authors: H Y Huang, Jinnkong Sheu, C H Chen, Y S Wu, W C LaiAbstract:We demonstrate a high-speed GaN-based light-emitting diode at a wavelength of around 500 nm for the application to plastic optical fiber communication. By use of the N-Type Doping in the GaN barrier layers of the InxGa1-xN-GaN-based multiple-quantum-well (MQW), superior performance of modulation-speed (120 versus 40 MHz) and output power to the undoped control under the same bias current has been observed. According to the measured electrical-to-optical bandwidths and extracted RC-limited bandwidths of both devices, the superior speed performance can be attributed to higher electron/hole radiative recombination rate in the n-doped MQW than that of undoped MQW
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modulation speed enhancement of a gan based green light emitting diode led by use of n type barrier Doping for plastic optical fiber pof communication
Quantum Electronics and Laser Science Conference, 2006Co-Authors: H Y Huang, Jinnkong Sheu, Gongru Lin, W C Lai, J I Chyi, Y S Wu, Ciling PanAbstract:We demonstrate a high-speed green GaN light-emitting-diode for plastic optical fiber communication. By use of N-Type Doping in barrier layers, superior performance of modulation-speed and output-power to undoped control has been observed.
