In this work, a hetero-epitaxial Al0.49In0.51As/Ga0.47In0.53 As metamorphic high electron mobility transistor(mHEMT) grown by metal–organic chemical vapor deposition(MOCVD) on p-type silicon substrate has been succes...In this work, a hetero-epitaxial Al0.49In0.51As/Ga0.47In0.53 As metamorphic high electron mobility transistor(mHEMT) grown by metal–organic chemical vapor deposition(MOCVD) on p-type silicon substrate has been successfully demonstrated. A novel AlGaAs/Al As period multiple quantum well(MQW) composite buffer scheme is developed to effectively tune the leakage current from the buffer layer. The quantized room-temperature Hall mobility of the twodimensional electron gas(2DEG) is larger than 7800 cm2/V·s, with an average sheet carrier density of 4.6×1012cm-2.Two-stage electron beam(EB) lithography technology by a JBX-6300 e-beam lithography system is developed to realize a 0.13-μm m HEMT device on Si substrate. A maximum transconductance Gm of up to 854 mS/mm is achieved, and is comparable to that of m HEMT technology on Ga As substrate with the same dimension. The fTand fmax are 135 GHz and120 GHz, respectively.展开更多
An optimal structure design of the lattice mismatched GaInP/GaInAs/Ge solar cell with high photoelectric conversion efficiency was proposed. Two-dimensional Bi2Te3/Sb2Te3 nanosheets were prepared by solvothermal synth...An optimal structure design of the lattice mismatched GaInP/GaInAs/Ge solar cell with high photoelectric conversion efficiency was proposed. Two-dimensional Bi2Te3/Sb2Te3 nanosheets were prepared by solvothermal synthesis method used as thermoelectric(TE) functional materials, which is further hybrid with high conductive reduced graphene oxide(rGO) and carbon nanotubes(CNTs). TE film was then fabricated based on above materials. The power factor of the n-type TE film is 19.31 μW/mK2, and the power factor of the p-type TE film is 97.40 μW/mK2. The flexible TE device was integrated with flexible solar cell. Compared with the single photovoltaic(PV) cell, the efficiency of the as-prepared flexible integrated device measured under the AM1.5 illumination is significantly improved. The efficiency of the two parallel tests is increased from 27.26% and 26.59%, to 29.11% and 28.92%, respectively. The increasing ratio reaches 6.7%-8.8%.展开更多
We directly grow a lattice matched GalnP/GalnAs/GalnNAs/Ge （1.88 eVil .42 eVil .05 eV/0.67eV） four-junction （4J） solar cell on a Ge substrate by the metal organic chemical vapor deposition technology. To solve the...We directly grow a lattice matched GalnP/GalnAs/GalnNAs/Ge （1.88 eVil .42 eVil .05 eV/0.67eV） four-junction （4J） solar cell on a Ge substrate by the metal organic chemical vapor deposition technology. To solve the current limit of the GalnNAs sub cell, we design three kinds of anti-reflection coatings and adjust the base region thickness of the GalnNAs sub cell. Developed by a series of experiments, the external quantum efficiency of the GalnNAs sub cell exceeds 80%, and its current density reaches 11.24 mA/cm2. Therefore the current limit of the 4J solar cell is significantly improved. Moreover, we discuss the difference of test results between 4J and GalnP/GalnAs/Ge solar cells under the 1 sun AMO spectrum.展开更多
基金supported by the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.61401373)the Fundamental Research Funds for Central University,China(Grant Nos.XDJK2013B004 and 2362014XK13)the Chongqing Natural Science Foundation,China(Grant No.cstc2014jcyj A40038)
文摘In this work, a hetero-epitaxial Al0.49In0.51As/Ga0.47In0.53 As metamorphic high electron mobility transistor(mHEMT) grown by metal–organic chemical vapor deposition(MOCVD) on p-type silicon substrate has been successfully demonstrated. A novel AlGaAs/Al As period multiple quantum well(MQW) composite buffer scheme is developed to effectively tune the leakage current from the buffer layer. The quantized room-temperature Hall mobility of the twodimensional electron gas(2DEG) is larger than 7800 cm2/V·s, with an average sheet carrier density of 4.6×1012cm-2.Two-stage electron beam(EB) lithography technology by a JBX-6300 e-beam lithography system is developed to realize a 0.13-μm m HEMT device on Si substrate. A maximum transconductance Gm of up to 854 mS/mm is achieved, and is comparable to that of m HEMT technology on Ga As substrate with the same dimension. The fTand fmax are 135 GHz and120 GHz, respectively.
文摘An optimal structure design of the lattice mismatched GaInP/GaInAs/Ge solar cell with high photoelectric conversion efficiency was proposed. Two-dimensional Bi2Te3/Sb2Te3 nanosheets were prepared by solvothermal synthesis method used as thermoelectric(TE) functional materials, which is further hybrid with high conductive reduced graphene oxide(rGO) and carbon nanotubes(CNTs). TE film was then fabricated based on above materials. The power factor of the n-type TE film is 19.31 μW/mK2, and the power factor of the p-type TE film is 97.40 μW/mK2. The flexible TE device was integrated with flexible solar cell. Compared with the single photovoltaic(PV) cell, the efficiency of the as-prepared flexible integrated device measured under the AM1.5 illumination is significantly improved. The efficiency of the two parallel tests is increased from 27.26% and 26.59%, to 29.11% and 28.92%, respectively. The increasing ratio reaches 6.7%-8.8%.
文摘We directly grow a lattice matched GalnP/GalnAs/GalnNAs/Ge （1.88 eVil .42 eVil .05 eV/0.67eV） four-junction （4J） solar cell on a Ge substrate by the metal organic chemical vapor deposition technology. To solve the current limit of the GalnNAs sub cell, we design three kinds of anti-reflection coatings and adjust the base region thickness of the GalnNAs sub cell. Developed by a series of experiments, the external quantum efficiency of the GalnNAs sub cell exceeds 80%, and its current density reaches 11.24 mA/cm2. Therefore the current limit of the 4J solar cell is significantly improved. Moreover, we discuss the difference of test results between 4J and GalnP/GalnAs/Ge solar cells under the 1 sun AMO spectrum.
