In order to suppress the electron leakage to p-type region of near-ultraviolet GaN/In_xGa_（1-x ）N/GaN multiple-quantumwell（MQW） laser diode（LD）, the Al composition of inserted p-type AlxGa_（1-x）N electron bloc...In order to suppress the electron leakage to p-type region of near-ultraviolet GaN/In_xGa_（1-x ）N/GaN multiple-quantumwell（MQW） laser diode（LD）, the Al composition of inserted p-type AlxGa_（1-x）N electron blocking layer（EBL） is optimized in an effective way, but which could only partially enhance the performance of LD. Here, due to the relatively shallow GaN/In_（0.04）Ga_（0.96）N/GaN quantum well, the hole leakage to n-type region is considered in the ultraviolet LD. To reduce the hole leakage, a 10-nm n-type Al_xGa_（1-x）N hole blocking layer（HBL） is inserted between n-type waveguide and the first quantum barrier, and the effect of Al composition of Al_xGa_（1-x）N HBL on LD performance is studied. Numerical simulations by the LASTIP reveal that when an appropriate Al composition of Al_xGa_（1-x）N HBL is chosen, both electron leakage and hole leakage can be reduced dramatically, leading to a lower threshold current and higher output power of LD.展开更多
The origin of the efficiency drop of quantum dot light-emitting diode(QLED)under consecutive voltage sweeps is still a puzzle.In this work,we report the voltage sweep behavior of QLED.We observed the efficiency drop o...The origin of the efficiency drop of quantum dot light-emitting diode(QLED)under consecutive voltage sweeps is still a puzzle.In this work,we report the voltage sweep behavior of QLED.We observed the efficiency drop of red QLED with ZnMgO electron transport layer(ETL)under consecutive voltage sweeps.In contrast,the efficiency increases for ZnO ETL device.By analyzing the electrical characteristics of both devices and surface traps of ZnMgO and ZnO nanoparticles,we found the efficiency drop of ZnMgO device is related to the hole leakage mediated by trap state on ZnMgO nanoparticles.For ZnO device,the efficiency raise is due to suppressed electron leakage.The hole leakage also causes rapid lifetime degradation of ZnMgO device.However,the efficiency and lifetime degradation of ZnMgO device can be eliminated with shelf aging.Our work reveals the distinct voltage sweep behavior of QLED based on different ETLs and may help to understand the lifetime degradation mechanism in QLED.展开更多
基金Project supported by the Science Challenge Project,China(Grant No.Z2016003)the National Key R&D Program of China(Grant Nos.2016YFB0400803and 2016YFB0401801)+1 种基金the National Natural Science Foundation of China(Grant Nos.61674138,61674139,61604145,61574135,61574134,61474142,61474110,61377020,and 61376089)the Beijing Municipal Science and Technology Project,China(Grant No.Z161100002116037)
文摘In order to suppress the electron leakage to p-type region of near-ultraviolet GaN/In_xGa_（1-x ）N/GaN multiple-quantumwell（MQW） laser diode（LD）, the Al composition of inserted p-type AlxGa_（1-x）N electron blocking layer（EBL） is optimized in an effective way, but which could only partially enhance the performance of LD. Here, due to the relatively shallow GaN/In_（0.04）Ga_（0.96）N/GaN quantum well, the hole leakage to n-type region is considered in the ultraviolet LD. To reduce the hole leakage, a 10-nm n-type Al_xGa_（1-x）N hole blocking layer（HBL） is inserted between n-type waveguide and the first quantum barrier, and the effect of Al composition of Al_xGa_（1-x）N HBL on LD performance is studied. Numerical simulations by the LASTIP reveal that when an appropriate Al composition of Al_xGa_（1-x）N HBL is chosen, both electron leakage and hole leakage can be reduced dramatically, leading to a lower threshold current and higher output power of LD.
基金supported by Key-Area Research and Development Program of Guangdong Province(Nos.2019B010925001 and 2019B010924001)Guangdong University Key Laboratory for Advanced Quantum Dot Displays and Lighting(No.2017KSYS007).
文摘The origin of the efficiency drop of quantum dot light-emitting diode(QLED)under consecutive voltage sweeps is still a puzzle.In this work,we report the voltage sweep behavior of QLED.We observed the efficiency drop of red QLED with ZnMgO electron transport layer(ETL)under consecutive voltage sweeps.In contrast,the efficiency increases for ZnO ETL device.By analyzing the electrical characteristics of both devices and surface traps of ZnMgO and ZnO nanoparticles,we found the efficiency drop of ZnMgO device is related to the hole leakage mediated by trap state on ZnMgO nanoparticles.For ZnO device,the efficiency raise is due to suppressed electron leakage.The hole leakage also causes rapid lifetime degradation of ZnMgO device.However,the efficiency and lifetime degradation of ZnMgO device can be eliminated with shelf aging.Our work reveals the distinct voltage sweep behavior of QLED based on different ETLs and may help to understand the lifetime degradation mechanism in QLED.
