Direct-current transfer characteristics of （InGaN）/A1GaN/A1N/GaN heterojunction field effect transistors （HFETs） are presented. A drain current plateau （IDs = 32.0 mA/mm） for Vcs swept from ＋0.7 V to -0. 6 V is...Direct-current transfer characteristics of （InGaN）/A1GaN/A1N/GaN heterojunction field effect transistors （HFETs） are presented. A drain current plateau （IDs = 32.0 mA/mm） for Vcs swept from ＋0.7 V to -0. 6 V is present in the transfer characteristics of InGaN/AIGaN/AIN/GaN HFETs. The theoretical calculation shows the coexistence of two-dimensional electron gas （2DEG） and two-dimensional hole gas （2DHG） in InGaN/AIGaN/A1N/GaN heterostructures, and the screening effect of 2DHG to the 2DEG in the conduction channel can explain this current plateau. Moreover, the current plateau shows the time-dependent behavior when IDs Vcs scans repeated are conducted. The obtained insight provides indication for the design in the fabrication of GaN-based super HFETs.展开更多
Electrical and optical properties of InGaN/AlGaN double heterostructure blue light-emitting diodes were investigated.Measurement of the forward bias current-voltage behaviour of the device demonstrated a departure fro...Electrical and optical properties of InGaN/AlGaN double heterostructure blue light-emitting diodes were investigated.Measurement of the forward bias current-voltage behaviour of the device demonstrated a departure from the Shockley model of a p-n diode,and it was observed that the dominant mechanism of carrier transport across the junction is associated with carrier tunnelling.Electroluminescence experiments indicated that there was a main emission band around 2.80 eV and a relatively weaker peak at 3.2 eV.A significant blueshift of the optical emission band was observed,which was consistent with the tunnelling character of electrical characteristics.Furthermore,the degradation in I-V characteristics and the low resistance ohmic short of the device were observed.展开更多
To improve the logic stability of conventional multi-valued logic（MVL） circuits designed with a GaNbased resonate tunneling diode（RTD）, we proposed a GaN/InGaN/AlGaN multi-quantum well（MQW） RTD. The proposed RTD...To improve the logic stability of conventional multi-valued logic（MVL） circuits designed with a GaNbased resonate tunneling diode（RTD）, we proposed a GaN/InGaN/AlGaN multi-quantum well（MQW） RTD. The proposed RTD was simulated through solving the coupled Schrodinger and Poisson equations in the numerical non-equilibrium Green＇s function（NEGF） method on the TCAD platform. The proposed RTD was grown layer by layer in epitaxial technologies. Simulated results indicate that its current-voltage characteristic appears to have a wider total negative differential resistance region than those of conventional ones and an obvious hysteresis loop at room temperature. To increase the Al composite of AIGaN barrier layers properly results in increasing of both the total negative differential resistance region width and the hysteresis loop width, which is helpful to improve the logic stability of MVL circuits. Moreover, the complement resonate tunneling transistor pair consisted of the proposed RTDs or the proposed RTD and enhanced mode HEMT controlled RTD8 is capable of generating versatile MVL modes at different supply voltages less than 3.3 V, which is very attractive for implementing more complex MVL function digital integrated circuits and systems with less devices, super high speed linear or nonlinear ADC and voltage sensors with a built-in super high speed ADC function.展开更多
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
基金Supported by the Knowledge Innovation Project of the Chinese Academy of Sciencesthe National Natural Science Foundation of China under Grant Nos 61204017 and 61334002+1 种基金the National Basic Research Program of Chinathe National Science and Technology Major Project of China
文摘Direct-current transfer characteristics of （InGaN）/A1GaN/A1N/GaN heterojunction field effect transistors （HFETs） are presented. A drain current plateau （IDs = 32.0 mA/mm） for Vcs swept from ＋0.7 V to -0. 6 V is present in the transfer characteristics of InGaN/AIGaN/AIN/GaN HFETs. The theoretical calculation shows the coexistence of two-dimensional electron gas （2DEG） and two-dimensional hole gas （2DHG） in InGaN/AIGaN/A1N/GaN heterostructures, and the screening effect of 2DHG to the 2DEG in the conduction channel can explain this current plateau. Moreover, the current plateau shows the time-dependent behavior when IDs Vcs scans repeated are conducted. The obtained insight provides indication for the design in the fabrication of GaN-based super HFETs.
基金国家自然科学基金(批准号:60676032,60276010,60376025,60276034)和北京市科技计划(批准号:H030430020230)资助项目 Project supported by the National Natural Science Foundation of China(Nos. 60676032,60276010,60376025,60276034) and the Beijing Scientific & Technical Program(No.H030130020230)
基金Supported by the National Natural Science Foundation of China under Grant Nos.69806006,69636010,69976017 and 69987001the National High Technology Research&Development Project of China(No.863-715-011-0030).
文摘Electrical and optical properties of InGaN/AlGaN double heterostructure blue light-emitting diodes were investigated.Measurement of the forward bias current-voltage behaviour of the device demonstrated a departure from the Shockley model of a p-n diode,and it was observed that the dominant mechanism of carrier transport across the junction is associated with carrier tunnelling.Electroluminescence experiments indicated that there was a main emission band around 2.80 eV and a relatively weaker peak at 3.2 eV.A significant blueshift of the optical emission band was observed,which was consistent with the tunnelling character of electrical characteristics.Furthermore,the degradation in I-V characteristics and the low resistance ohmic short of the device were observed.
基金Project supported by the National Natural Science Foundation of China(Nos.61302009,61571171)
文摘To improve the logic stability of conventional multi-valued logic（MVL） circuits designed with a GaNbased resonate tunneling diode（RTD）, we proposed a GaN/InGaN/AlGaN multi-quantum well（MQW） RTD. The proposed RTD was simulated through solving the coupled Schrodinger and Poisson equations in the numerical non-equilibrium Green＇s function（NEGF） method on the TCAD platform. The proposed RTD was grown layer by layer in epitaxial technologies. Simulated results indicate that its current-voltage characteristic appears to have a wider total negative differential resistance region than those of conventional ones and an obvious hysteresis loop at room temperature. To increase the Al composite of AIGaN barrier layers properly results in increasing of both the total negative differential resistance region width and the hysteresis loop width, which is helpful to improve the logic stability of MVL circuits. Moreover, the complement resonate tunneling transistor pair consisted of the proposed RTDs or the proposed RTD and enhanced mode HEMT controlled RTD8 is capable of generating versatile MVL modes at different supply voltages less than 3.3 V, which is very attractive for implementing more complex MVL function digital integrated circuits and systems with less devices, super high speed linear or nonlinear ADC and voltage sensors with a built-in super high speed ADC function.
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National Natural Science Foundation of China(No.62204127)the Natural Science Foundation of Jiangsu Province(No.BK20215093)State Key Laboratory of Luminescence and Applications(No.SKLA‒2021‒04)。
