The role of the oxygen in AlGaN/GaN high electron mobility transistors(HEMTs)before and after semi-on state stress was discussed.Comparing with the electrical characteristics of the devices in vacuum,air,and oxygen at...The role of the oxygen in AlGaN/GaN high electron mobility transistors(HEMTs)before and after semi-on state stress was discussed.Comparing with the electrical characteristics of the devices in vacuum,air,and oxygen atmosphere,it is revealed that the oxygen has significant influence on the electric characteristics and the hot-carrier-stress-induced degradation of the device.Comparing with the situation in vacuum,the gate leakage increased an order of magnitude in oxygen and air atmosphere.Double gate structure was used to separate the barrier leakage and surface leakage of AlGaN/GaN HEMT it is found that surface leakage is the major influencing factor in gate leakage of SiN-passivated devices before and after semi-on state stress.During semi-on state stress in the oxygen atmosphere,the electric-field-driven oxidation process promoted the oxidation of the nitride layer,and the oxidation layer in the SiN/AlGaN interface leads to the decreasing of the surface leakage.展开更多
Mechanoluminescent materials that convert mechanical stimuli to light emission have attracted extensive attention for potential applications in human-machine interactions. Here, we report a simple and available novel ...Mechanoluminescent materials that convert mechanical stimuli to light emission have attracted extensive attention for potential applications in human-machine interactions. Here, we report a simple and available novel approach for the oxygen-assisted preparation of ZnS：Mn particles by solid-state reaction at atmospheric pressure without the formation of the corresponding oxides. The existence of O2 has a positive impact on the formation of S vacancies in wurtzite-phase ZnS, leading to the introduction of Mn2＋ ion luminescent centers and shallow donor levels, which can improve the electron-hole recombination rate. The O2 ratio and Mn2＋ ion doping concentration have significant effects on the luminous efficienc）5 which is optimal at 1%-20% and 1 at.%-2 at.% respectively. In addition, a device based on the piezo-photonic effect with excellent pressure sensitivity of 0.032 MPa-1 was fabricated, which can map the two-dimensional pressure distribution ranging from 2.2 to 40.6 MPa in situ. This device can be applied to real-time pressure mapping, smart sensor networks, high-level security systems, human-machine interfaces, and artificial skins.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62104167)the Natural Science Foundation of Jiangsu Province,China(Grant Nos.BK20210863 and BK20180966)by Qing Lan Project of Jiangsu Province,China.
文摘The role of the oxygen in AlGaN/GaN high electron mobility transistors(HEMTs)before and after semi-on state stress was discussed.Comparing with the electrical characteristics of the devices in vacuum,air,and oxygen atmosphere,it is revealed that the oxygen has significant influence on the electric characteristics and the hot-carrier-stress-induced degradation of the device.Comparing with the situation in vacuum,the gate leakage increased an order of magnitude in oxygen and air atmosphere.Double gate structure was used to separate the barrier leakage and surface leakage of AlGaN/GaN HEMT it is found that surface leakage is the major influencing factor in gate leakage of SiN-passivated devices before and after semi-on state stress.During semi-on state stress in the oxygen atmosphere,the electric-field-driven oxidation process promoted the oxidation of the nitride layer,and the oxidation layer in the SiN/AlGaN interface leads to the decreasing of the surface leakage.
基金The authors are thankful for support from National Natural Science Foundation of China （Nos. 51622205, 61675027, 61405040, 51432005, 61505010, and 51502018）, National Key R ＆ D project from Minister of Science and Technology, China （No. 2016YFA0202703）, National Postdoctoral Program for Innovative Talents （No. BX201600040）, China Postdoctoral Science Foundation Funded Project （No. 2016M600976） and the ＂Thousand Talents＂ program of China for pioneering researchers and innovative teams.
文摘Mechanoluminescent materials that convert mechanical stimuli to light emission have attracted extensive attention for potential applications in human-machine interactions. Here, we report a simple and available novel approach for the oxygen-assisted preparation of ZnS：Mn particles by solid-state reaction at atmospheric pressure without the formation of the corresponding oxides. The existence of O2 has a positive impact on the formation of S vacancies in wurtzite-phase ZnS, leading to the introduction of Mn2＋ ion luminescent centers and shallow donor levels, which can improve the electron-hole recombination rate. The O2 ratio and Mn2＋ ion doping concentration have significant effects on the luminous efficienc）5 which is optimal at 1%-20% and 1 at.%-2 at.% respectively. In addition, a device based on the piezo-photonic effect with excellent pressure sensitivity of 0.032 MPa-1 was fabricated, which can map the two-dimensional pressure distribution ranging from 2.2 to 40.6 MPa in situ. This device can be applied to real-time pressure mapping, smart sensor networks, high-level security systems, human-machine interfaces, and artificial skins.
