ZnO tetrapods were synthesized by a typical thermal vapor-solid deposition method in a horizontal tube furnace.Structural characterization was carried out by transmission electron microscopy （TEM） and select-area el...ZnO tetrapods were synthesized by a typical thermal vapor-solid deposition method in a horizontal tube furnace.Structural characterization was carried out by transmission electron microscopy （TEM） and select-area electron diffraction （SAED）,which shows the presence of zinc blende nucleus in the center of tetrapods while the four branches taking hexagonal wurtzite structure.The electrical transport property of ZnO tetrapods was investigated through an in-situ nanoprobe system.The three branches of a tetrapod serve as source,drain,and ＂gate＂,respectively;while the fourth branch pointing upward works as the force trigger by vertically applying external force downward.The conductivity of each branch of ZnO-tetrapods increases 3-4 times under pressure.In such situation,the electrical current through the branches of ZnO tetrapods can be tuned by external force,and therefore a simple force sensor based on ZnO tetrapods has been demonstrated for the first time.展开更多
Rare earth element gadolinium-doped aluminum–zinc oxide（Gd–AZO） semiconductor thin film material was deposited on both silicon and glass substrate by radio frequency（RF） sputtering at room temperature.Electrical...Rare earth element gadolinium-doped aluminum–zinc oxide（Gd–AZO） semiconductor thin film material was deposited on both silicon and glass substrate by radio frequency（RF） sputtering at room temperature.Electrical properties and microstructure of Gd–AZO thin film were mainly modulated by altering O2 partial pressure（OPP） during the RF sputtering process.Scanning electron microscope（SEM） and X-ray diffraction（XRD） test were carried out to uncover the microstructure variation trend with the sputtering OPP,and amorphous structure which is beneficial to large mass industry manufacture was also demonstrated by the XRD pattern.Transmittance in visible light spectrum implies the potential application for Gd–AZO to be used in transparent material field.Finally,bottom gate,top contact device structure thin film transistors（TFTs） with Gd–AZO thin film as the active channel layer were fabricated to verify the semiconductor availability of Gd–AZO thin film material.Besides,the Gd–AZO TFTs exhibit preferable transfer and output characteristics.展开更多
An oxygen-deficient SrTiO3/La0.67Sr0.33MnO3 heterojunction is fabricated on an SrTiO3 （001） substrate by a pulsed laser deposition method. The electrical characteristics of the heterojunction are studied systematica...An oxygen-deficient SrTiO3/La0.67Sr0.33MnO3 heterojunction is fabricated on an SrTiO3 （001） substrate by a pulsed laser deposition method. The electrical characteristics of the heterojunction are studied systematically in a temperature range from 80 K to 300 K. The transport mechanism follows I ∝ exp （eV/nkT） under small forward bias, while it becomes space charge limited and follows I ∝ Vm（T） with 1.49〈 m 〈1.99 under high bias. Such a heterojunction also exhibits magnetoresistance （MR） effect. The absolute value of negative MR monotonically increases with temperature decreasing and reaches 26.7% at 80 K under H=0.7 T. Various factors, such as strain and oxygen deficiency play dominant roles in the characteristics.展开更多
The structural properties, band structures and densities of states of Sn-doped Ga1.375In0.625O3 with a Sn atom substituting for the Ga atom or a Sn atom substituting for the In atom are calculated by using the firstpr...The structural properties, band structures and densities of states of Sn-doped Ga1.375In0.625O3 with a Sn atom substituting for the Ga atom or a Sn atom substituting for the In atom are calculated by using the firstprinciples method. The substitution of the Sn atom for the Ga atom in Ga1.375In0.625O3（Ga1.25In0.625Sn0.125O3/has larger lattice parameters and stronger Sn–O ionic bonds than that of the substitutional doping of the Sn atom for the In atom in Ga1.375In0.625O3（Ga1.375In0.5Sn0.125O3/. Results show that the Sn atom is preferentially substituted for the In atom in Sn-doped Ga1.375In0.625O3. Sn-doped Ga1.375In0.625O3 exhibits n-type metallic conductivity,and the impurity bands are mainly provided by the Sn 5s states. The optical band gap of Ga1.375In0.5Sn0.125O3is larger than that of Ga1.25In0.625Sn0.125O3. Ga1.25In0.625Sn0.125O3 has a smaller electron effective mass and a slightly larger mobility. However, Ga1.375In0.5Sn0.125O3 has a larger relative electron number and a slightly higher conductivity.展开更多
基金supported by the China Scholarship Council (CSC) (No.20083019)Fundamental Research Funds for the Central Universities (Nos.21611603,21611424,and 216113143)+1 种基金Jinan University Start-up Funds (No.50624019)the Knowledge Innovation Program of the Chinese Academy of Sciences (No.KJCX2-YW-M13)
文摘ZnO tetrapods were synthesized by a typical thermal vapor-solid deposition method in a horizontal tube furnace.Structural characterization was carried out by transmission electron microscopy （TEM） and select-area electron diffraction （SAED）,which shows the presence of zinc blende nucleus in the center of tetrapods while the four branches taking hexagonal wurtzite structure.The electrical transport property of ZnO tetrapods was investigated through an in-situ nanoprobe system.The three branches of a tetrapod serve as source,drain,and ＂gate＂,respectively;while the fourth branch pointing upward works as the force trigger by vertically applying external force downward.The conductivity of each branch of ZnO-tetrapods increases 3-4 times under pressure.In such situation,the electrical current through the branches of ZnO tetrapods can be tuned by external force,and therefore a simple force sensor based on ZnO tetrapods has been demonstrated for the first time.
基金financially supported by the National Basic Research Program of China (No.2011CBA00600)the National Natural Science Foundation of China (No.61275025)
文摘Rare earth element gadolinium-doped aluminum–zinc oxide（Gd–AZO） semiconductor thin film material was deposited on both silicon and glass substrate by radio frequency（RF） sputtering at room temperature.Electrical properties and microstructure of Gd–AZO thin film were mainly modulated by altering O2 partial pressure（OPP） during the RF sputtering process.Scanning electron microscope（SEM） and X-ray diffraction（XRD） test were carried out to uncover the microstructure variation trend with the sputtering OPP,and amorphous structure which is beneficial to large mass industry manufacture was also demonstrated by the XRD pattern.Transmittance in visible light spectrum implies the potential application for Gd–AZO to be used in transparent material field.Finally,bottom gate,top contact device structure thin film transistors（TFTs） with Gd–AZO thin film as the active channel layer were fabricated to verify the semiconductor availability of Gd–AZO thin film material.Besides,the Gd–AZO TFTs exhibit preferable transfer and output characteristics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61078057,51172183,and 51202195)the Natural Science Foundation of Shaanxi Province,China(Grant No.2012JQ8013)+1 种基金the Aviation Foundation of China(Grant No.2011ZF53065)the Foundation for Fundamental Research of Northwestern Polytechnical University(NPU),China(Grant Nos.JC201155,JC201271,and JC20120246)
文摘An oxygen-deficient SrTiO3/La0.67Sr0.33MnO3 heterojunction is fabricated on an SrTiO3 （001） substrate by a pulsed laser deposition method. The electrical characteristics of the heterojunction are studied systematically in a temperature range from 80 K to 300 K. The transport mechanism follows I ∝ exp （eV/nkT） under small forward bias, while it becomes space charge limited and follows I ∝ Vm（T） with 1.49〈 m 〈1.99 under high bias. Such a heterojunction also exhibits magnetoresistance （MR） effect. The absolute value of negative MR monotonically increases with temperature decreasing and reaches 26.7% at 80 K under H=0.7 T. Various factors, such as strain and oxygen deficiency play dominant roles in the characteristics.
基金Project supported by the National Natural Science Foundation of China(No.10974077)the Innovation Project of Shandong Graduate Education,China(No.SDYY13093)
文摘The structural properties, band structures and densities of states of Sn-doped Ga1.375In0.625O3 with a Sn atom substituting for the Ga atom or a Sn atom substituting for the In atom are calculated by using the firstprinciples method. The substitution of the Sn atom for the Ga atom in Ga1.375In0.625O3（Ga1.25In0.625Sn0.125O3/has larger lattice parameters and stronger Sn–O ionic bonds than that of the substitutional doping of the Sn atom for the In atom in Ga1.375In0.625O3（Ga1.375In0.5Sn0.125O3/. Results show that the Sn atom is preferentially substituted for the In atom in Sn-doped Ga1.375In0.625O3. Sn-doped Ga1.375In0.625O3 exhibits n-type metallic conductivity,and the impurity bands are mainly provided by the Sn 5s states. The optical band gap of Ga1.375In0.5Sn0.125O3is larger than that of Ga1.25In0.625Sn0.125O3. Ga1.25In0.625Sn0.125O3 has a smaller electron effective mass and a slightly larger mobility. However, Ga1.375In0.5Sn0.125O3 has a larger relative electron number and a slightly higher conductivity.
