The characteristics of a blue light-emitting diode （LED） with an AIlnN/GaN superlattice （SL） electron-blocking layer （EBL） are analyzed numerically. The carder concentrations in the quantum wells, energy band di...The characteristics of a blue light-emitting diode （LED） with an AIlnN/GaN superlattice （SL） electron-blocking layer （EBL） are analyzed numerically. The carder concentrations in the quantum wells, energy band diagrams, electrostatic fields, and internal quantum efficiency are investigated. The results suggest that the LED with an AIInN/GaN SL EBL has better hole injection efficiency, lower electron leakage, and smaller electrostatic fields in the active region than the LED with a conventional rectangular AIGaN EBL or a A1GaN/GaN SL EBL. The results also indicate that the efficiency droop is markedly improved when an AlInN/GaN SL EBL is used.展开更多
The performance of InGaN blue light-emitting diodes（LEDs） with different kinds of electron-blocking layers is investigated numerically.We compare the simulated emission spectra,electron and hole concentrations,energ...The performance of InGaN blue light-emitting diodes（LEDs） with different kinds of electron-blocking layers is investigated numerically.We compare the simulated emission spectra,electron and hole concentrations,energy band diagrams,electrostatic fields,and internal quantum efficiencies of the LEDs.The LED using AlGaN with gradually increasing Al content from 0% to 20% as the electron-blocking layer（EBL） has a strong spectrum intensity,mitigates efficiency droop,and possesses higher output power compared with the LEDs with the other three types of EBLs.These advantages could be because of the lower electron leakage current and more effective hole injection.The optical performance of the specifically designed LED is also improved in the case of large injection current.展开更多
P-A1GaN/P-GaN superlattices are investigated in blue InGaN light-emitting diodes as electron blocking layers. The simulation results show that efficiency droop is markedly improved due to two reasons： （i） enhanced ...P-A1GaN/P-GaN superlattices are investigated in blue InGaN light-emitting diodes as electron blocking layers. The simulation results show that efficiency droop is markedly improved due to two reasons： （i） enhanced hole concentration and hole carrier transport efficiency in A1GaN/GaN superlattices, and （ii） enhanced blocking of electron overflow between multiple quantum-wells and A1CaN/GaN superlattices.展开更多
An improved GaN film with low dislocation density was grown on a C-face patterned sapphire substrate （PSS） by metalorganic chemical vapor deposition （MOCVD）. The vapor phase epitaxy starts from the regions with no...An improved GaN film with low dislocation density was grown on a C-face patterned sapphire substrate （PSS） by metalorganic chemical vapor deposition （MOCVD）. The vapor phase epitaxy starts from the regions with no etched pits and then spreads laterally to form a continuous GaN film. The properties of the GaN film have been investigated by double crystal X-ray diffraction （DCXRD）, atomic force microscopy （AFM） and photoluminescence （PL）, respectively. The full-width at half-maximum （FWHM） of the X-ray diffraction curves （XRCs） for the GaN film grown on PSS in the （0002） plane and the （1012） plane are as low as 312.80 arcsec and 298.08 acrsec, respectively. The root mean square （RMS） of the GaN film grown on PSS is 0.233 nm and the intensity of the PL peak is comparatively strong.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 61176043)the Special Funds for Provincial Strategic and Emerging Industries Projects of Guangdong, China (Grant Nos. 2010A081002005, 2011A081301003, and 2012A080304016)
文摘The characteristics of a blue light-emitting diode （LED） with an AIlnN/GaN superlattice （SL） electron-blocking layer （EBL） are analyzed numerically. The carder concentrations in the quantum wells, energy band diagrams, electrostatic fields, and internal quantum efficiency are investigated. The results suggest that the LED with an AIInN/GaN SL EBL has better hole injection efficiency, lower electron leakage, and smaller electrostatic fields in the active region than the LED with a conventional rectangular AIGaN EBL or a A1GaN/GaN SL EBL. The results also indicate that the efficiency droop is markedly improved when an AlInN/GaN SL EBL is used.
基金Project supported by the National Natural Science Foundation of China(Grant No.61176043)the Fund for Strategic and Emerging Industries of Guangdong Province,China(Grant No.2010A081002005)the Project of Combination of Production and Research of the Education Ministry and Guangdong Province,China(Grant No.2010B090400192)
文摘The performance of InGaN blue light-emitting diodes（LEDs） with different kinds of electron-blocking layers is investigated numerically.We compare the simulated emission spectra,electron and hole concentrations,energy band diagrams,electrostatic fields,and internal quantum efficiencies of the LEDs.The LED using AlGaN with gradually increasing Al content from 0% to 20% as the electron-blocking layer（EBL） has a strong spectrum intensity,mitigates efficiency droop,and possesses higher output power compared with the LEDs with the other three types of EBLs.These advantages could be because of the lower electron leakage current and more effective hole injection.The optical performance of the specifically designed LED is also improved in the case of large injection current.
基金Project supported by the Project of Combination of Production and Research Guided by Education Ministry of China in 2009(Grant No. 2009B090300338)the LED Industrial Projects of Special Funds Strategic Emerging Industries in 2011,Guangdong Province,China (Grant No. 2010A081002005)
文摘P-A1GaN/P-GaN superlattices are investigated in blue InGaN light-emitting diodes as electron blocking layers. The simulation results show that efficiency droop is markedly improved due to two reasons： （i） enhanced hole concentration and hole carrier transport efficiency in A1GaN/GaN superlattices, and （ii） enhanced blocking of electron overflow between multiple quantum-wells and A1CaN/GaN superlattices.
基金supported by the National Natural Science Foundation of China (No. 50602018)
文摘An improved GaN film with low dislocation density was grown on a C-face patterned sapphire substrate （PSS） by metalorganic chemical vapor deposition （MOCVD）. The vapor phase epitaxy starts from the regions with no etched pits and then spreads laterally to form a continuous GaN film. The properties of the GaN film have been investigated by double crystal X-ray diffraction （DCXRD）, atomic force microscopy （AFM） and photoluminescence （PL）, respectively. The full-width at half-maximum （FWHM） of the X-ray diffraction curves （XRCs） for the GaN film grown on PSS in the （0002） plane and the （1012） plane are as low as 312.80 arcsec and 298.08 acrsec, respectively. The root mean square （RMS） of the GaN film grown on PSS is 0.233 nm and the intensity of the PL peak is comparatively strong.
