Specific contact resistance to p-GaN was measured for various structures of Ni/Pd-based metals and thin(20-30 nm thick)p-InGaN/p^(+)-GaN contacting layers.The effects of surface chemical treatment and annealing temper...Specific contact resistance to p-GaN was measured for various structures of Ni/Pd-based metals and thin(20-30 nm thick)p-InGaN/p^(+)-GaN contacting layers.The effects of surface chemical treatment and annealing temperature were ex-amined.The optimal annealing temperature was determined to be 550°C,above which the sheet resistance of the samples de-graded considerably,suggesting that undesirable alloying had occurred.Pd-containing metal showed~35%lower com-pared to that of single Ni.Very thin(2-3.5 nm thick)p-InGaN contacting layers grown on 20-25 nm thick p^(+)-GaN layers exhib-ited one to two orders of magnitude smaller values of compared to that of p^(+)-GaN without p-InGaN.The current density de-pendence of,which is indicative of nonlinearity in current-voltage relation,was also examined.The lowest achieved through this study was 4.9×10^(-5)Ω·cm^(2)@J=3.4 kA/cm^(2).展开更多
A suitable contacting scheme for p-(Al)GaN facilitating quick feedback and accurate measurements is proposed in this study.22 nm p^(+)-GaN followed by 2 nm p-In_(0.2)Ga_(0.8)N was grown on p-type layers by metal-organ...A suitable contacting scheme for p-(Al)GaN facilitating quick feedback and accurate measurements is proposed in this study.22 nm p^(+)-GaN followed by 2 nm p-In_(0.2)Ga_(0.8)N was grown on p-type layers by metal-organic chemical vapor deposition.Samples were then cut into squares after annealing and contact electrodes using In balls were put at the corners of the squares.Good linearity between all the electrodes was confirmed inⅠ–Ⅴcurves during Hall measurements even with In metal.Serval samples taken from the same wafer showed small standard deviation of~4%for resistivity,Hall mobility and hole concentration.The influence of contact layer on the electrical characteristics of bulk p-type layers was then investigated by step etching technique using inductively coupled plasma etching and subsequent Hall-effect measurements.Identical values could be obtained consistently when a 28 nm non-conductive layer thickness at the surface was taken into account.Therefore,the procedures for evaluating the electrical properties of GaN-based p-type layers just using In balls proposed in this study are shown to be quick and useful as for the other conventionalⅢ–Ⅴmaterials.展开更多
Relationship between the hole concentration at room temperature and the Mg doping concentration in p-GaN grown by MOCVD after sufficient annealing was studied in this paper.Different annealing conditions were applied ...Relationship between the hole concentration at room temperature and the Mg doping concentration in p-GaN grown by MOCVD after sufficient annealing was studied in this paper.Different annealing conditions were applied to obtain sufficient activation for p-GaN samples with different Mg doping ranges.Hole concentration,resistivity and mobility were characterized by room-temperature Hall measurements.The Mg doping concentration and the residual impurities such as H,C,O and Si were measured by secondary ion mass spectroscopy,confirming negligible compensations by the impurities.The hole concentration,resistivity and mobility data are presented as a function of Mg concentration,and are compared with literature data.The appropriate curve relating the Mg doping concentration to the hole concentration is derived using a charge neutrality equation and the ionized-acceptor-density[N-(A)^(-)](cm^(−3))dependent ionization energy of Mg acceptor was determined asE_(A)^(Mg)=184−2.66×10^(−5)×[N_(A)^(-)]1/3 meV.展开更多
[ Objective ] The research aimed to develop anti-aging masks with aqueous extracts of Ganoderma lucidum and to study the clinical efficacy on the delaying of skin aging. [Method] The anti-aging efficacy of the aqueous...[ Objective ] The research aimed to develop anti-aging masks with aqueous extracts of Ganoderma lucidum and to study the clinical efficacy on the delaying of skin aging. [Method] The anti-aging efficacy of the aqueous extract of C.anoderrna luciclum was evaluated by sensory evaluation, safety evaluation, instrumental measurements, etc. [ Result] The results of sensory evaluation showed that after continuous application of the test materials for 12 weeks, the skin dryness, elasticity, surface sheen, fine wrinkles and smoothness were well improved, and the improvement rates were 9l. 17%, 91.17% , 94.12% , 11.76% and 91.18% , respectively. The measurement results by specialized instrument showed that the skin hydration on the target site increased continuously with the prolonging of the using time. Significant differences existed between each time point after using the products and the time before using. There was no signiScant difference existed in elasticity index 112 and R5 compared with before using. [Result] Clinical data showed that the active ingredients in aqueous extract of Ganoderma lucidum had a certain effect on the delaying of skin aging.展开更多
基金the National Key Research and Development Program of China(2017YFE0131500)the Key Research and Development Program of Guangdong Province(2020B090922001)+2 种基金National Natural Science Foundation of China(61834008)Key Research and Development Program of Jiangsu province(BE2020004,BE2021008-1)Guangdong Basic and Applied Basic Research Foundation(2019B1515120091).
文摘Specific contact resistance to p-GaN was measured for various structures of Ni/Pd-based metals and thin(20-30 nm thick)p-InGaN/p^(+)-GaN contacting layers.The effects of surface chemical treatment and annealing temperature were ex-amined.The optimal annealing temperature was determined to be 550°C,above which the sheet resistance of the samples de-graded considerably,suggesting that undesirable alloying had occurred.Pd-containing metal showed~35%lower com-pared to that of single Ni.Very thin(2-3.5 nm thick)p-InGaN contacting layers grown on 20-25 nm thick p^(+)-GaN layers exhib-ited one to two orders of magnitude smaller values of compared to that of p^(+)-GaN without p-InGaN.The current density de-pendence of,which is indicative of nonlinearity in current-voltage relation,was also examined.The lowest achieved through this study was 4.9×10^(-5)Ω·cm^(2)@J=3.4 kA/cm^(2).
基金financially supported by the National Key Research and Development Program of China(2017YFE0131500)the Key Research and Development Program of Guangdong Province(2020B090922001)+2 种基金National Natural Science Foundation of China(61834008,62150710548)Key Research and Development Program of Jiangsu province(BE2020004,BE2021008-1)Guangdong Basic and Applied Basic Research Foundation(2019B1515120091)。
文摘A suitable contacting scheme for p-(Al)GaN facilitating quick feedback and accurate measurements is proposed in this study.22 nm p^(+)-GaN followed by 2 nm p-In_(0.2)Ga_(0.8)N was grown on p-type layers by metal-organic chemical vapor deposition.Samples were then cut into squares after annealing and contact electrodes using In balls were put at the corners of the squares.Good linearity between all the electrodes was confirmed inⅠ–Ⅴcurves during Hall measurements even with In metal.Serval samples taken from the same wafer showed small standard deviation of~4%for resistivity,Hall mobility and hole concentration.The influence of contact layer on the electrical characteristics of bulk p-type layers was then investigated by step etching technique using inductively coupled plasma etching and subsequent Hall-effect measurements.Identical values could be obtained consistently when a 28 nm non-conductive layer thickness at the surface was taken into account.Therefore,the procedures for evaluating the electrical properties of GaN-based p-type layers just using In balls proposed in this study are shown to be quick and useful as for the other conventionalⅢ–Ⅴmaterials.
基金supported by the National Natural Science Foundation of China(62150710548,61834008,U21A20493)the National Key Research and Development Program of China(2022YFB2802801)+2 种基金the Key Research and Development Program of Jiangsu Province(BE2021008-1)the Suzhou Key Laboratory of New-type Laser Display Technology(SZS2022007)the Natural Science Foundation of Jiangsu Province(BK20232042).
文摘Relationship between the hole concentration at room temperature and the Mg doping concentration in p-GaN grown by MOCVD after sufficient annealing was studied in this paper.Different annealing conditions were applied to obtain sufficient activation for p-GaN samples with different Mg doping ranges.Hole concentration,resistivity and mobility were characterized by room-temperature Hall measurements.The Mg doping concentration and the residual impurities such as H,C,O and Si were measured by secondary ion mass spectroscopy,confirming negligible compensations by the impurities.The hole concentration,resistivity and mobility data are presented as a function of Mg concentration,and are compared with literature data.The appropriate curve relating the Mg doping concentration to the hole concentration is derived using a charge neutrality equation and the ionized-acceptor-density[N-(A)^(-)](cm^(−3))dependent ionization energy of Mg acceptor was determined asE_(A)^(Mg)=184−2.66×10^(−5)×[N_(A)^(-)]1/3 meV.
基金Supported by Comprehensive Strategic Cooperation Project of Chinese Academy of Sciences in Guangdong Province(2011B090300075)Guangzhou Special Project with Benefaction for People(2014Y2-00130)Fund Project of Transformation of Agricultural Science and Technology Achievements(2013GB2E000360)
文摘[ Objective ] The research aimed to develop anti-aging masks with aqueous extracts of Ganoderma lucidum and to study the clinical efficacy on the delaying of skin aging. [Method] The anti-aging efficacy of the aqueous extract of C.anoderrna luciclum was evaluated by sensory evaluation, safety evaluation, instrumental measurements, etc. [ Result] The results of sensory evaluation showed that after continuous application of the test materials for 12 weeks, the skin dryness, elasticity, surface sheen, fine wrinkles and smoothness were well improved, and the improvement rates were 9l. 17%, 91.17% , 94.12% , 11.76% and 91.18% , respectively. The measurement results by specialized instrument showed that the skin hydration on the target site increased continuously with the prolonging of the using time. Significant differences existed between each time point after using the products and the time before using. There was no signiScant difference existed in elasticity index 112 and R5 compared with before using. [Result] Clinical data showed that the active ingredients in aqueous extract of Ganoderma lucidum had a certain effect on the delaying of skin aging.
