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Effect of Si doping in wells of AlGaN/GaN superlattice on the characteristics of epitaxial layer 被引量:1
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作者 张伟 薛军帅 +4 位作者 周晓伟 张月 刘子阳 张进成 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第7期455-459,共5页
An A1GaN/GaN superlattice grown on the top of a GaN buffer induces the broadening of the full width at half maximum of (102) and (002) X-ray diffraction rocking curves. With an increase in the Si-doped concentrati... An A1GaN/GaN superlattice grown on the top of a GaN buffer induces the broadening of the full width at half maximum of (102) and (002) X-ray diffraction rocking curves. With an increase in the Si-doped concentration in the GaN wells, the full width at half maximum of the (102) rocking curves decreases, while that of the (002) rocking curves increases. A significant increase of the full width at the half maximum of the (002) rocking curves when the doping concentration reaches 2.5 × 10^19 cm-3 indicates the substantial increase of the inclined threading dislocation. High level doping in the A1GaN/GaN superlattice can greatly reduce the biaxial stress and optimize the surface roughness of the structures grown on the top of it. 展开更多
关键词 a1gan/gan superlattice si doping
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Structure and Strain Properties of GaN Films Grown on Si(111) Substrates with AlxGa1-xN/AlyGa1-yN Superlattices
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作者 潘磊 倪金玉 +5 位作者 郁鑫鑫 董逊 彭大青 李传皓 李忠辉 陈堂胜 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第5期153-156,共4页
CaN films with an AlxGa1-xN/AlyGa1-xN superlattice (SL) buffer layer are grown on Si(111) substrates by metal-organic chemical vapor deposition (MOCVD). The structure and strain properties of the samples are stu... CaN films with an AlxGa1-xN/AlyGa1-xN superlattice (SL) buffer layer are grown on Si(111) substrates by metal-organic chemical vapor deposition (MOCVD). The structure and strain properties of the samples are studied by optical microscopy, Raman spectroscopy, x-ray diffractometry and atomic force microscopy. The results show that the strain status and crystalline quality of the CaN layers are strongly dependent on the difference of the Al composition between AlxCa1-xN barriers and AlyCa1-yN wells in the SLs. With a large Al composition difference, the CaN film tends to generate cracks on the surface due to the severe relaxation of the SLs. Otherwise, when using a small Al composition difference, the crystalline quality of the CaN layer degrades due to the poor function of the SLs in filtering dislocations. Under an optimized condition that the Al composition difference equals 0.1, the crack-free and compressive strained CaN film with an improved crystalline quality is achieved. Therefore, the AlxGa1-xN/AlyGal-yN SL buffer layer is a promising buffer structure for growing thick CaN films on Si substrates without crack generation. 展开更多
关键词 gan x)N/Al_yGa y)N superlattices Substrates with Al_xGa Structure and Strain Properties of gan Films Grown on si
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The influence of AlN/GaN superlattice intermediate layer on the properties of GaN grown on Si(111) substrates 被引量:2
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作者 刘喆 王晓亮 +3 位作者 王军喜 胡国新 郭伦春 李晋闽 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第5期1467-1471,共5页
AlN/GaN superlattice buffer is inserted between GaN epitaxiai layer and Si substrate before epitaxiai growth of GaN layer. High-quality and crack-free GaN epitaxiai layers can be obtained by inserting AlN/GaN superlat... AlN/GaN superlattice buffer is inserted between GaN epitaxiai layer and Si substrate before epitaxiai growth of GaN layer. High-quality and crack-free GaN epitaxiai layers can be obtained by inserting AlN/GaN superlattice buffer layer. The influence of AlN/GaN superlattice buffer layer on the properties of GaN films are investigated in this paper. One of the important roles of the superlattice is to release tensile strain between Si substrate and epilayer. Raman spectra show a substantial decrease of in-plane tensile strain in GaN layers by using AlN/GaN superlattice buffer layer. Moreover, TEM cross-sectional images show that the densities of both screw and edge dislocations are significantly reduced. The GaN films grown on Si with the superlattice buffer also have better surface morphology and optical properties. 展开更多
关键词 gan si substrate metalorganic chemical vapour deposition superlattice buffer
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Performance enhancement of an InGaN light-emitting diode with an AlGaN/InGaN superlattice electron-blocking layer
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作者 熊建勇 许毅钦 +5 位作者 赵芳 宋晶晶 丁彬彬 郑树文 张涛 范广涵 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第10期626-630,共5页
The efficiency enhancement of an InGaN light-emitting diode (LED) with an A1GaN/InGaN superlattice (SL) electron-blocking layer (EBL) is studied numerically, which involves the light-current performance curve, i... The efficiency enhancement of an InGaN light-emitting diode (LED) with an A1GaN/InGaN superlattice (SL) electron-blocking layer (EBL) is studied numerically, which involves the light-current performance curve, internal quan- tum efficiency electrostatic field band wavefunction, energy band diagram carrier concentration, electron current density, and radiative recombination rate. The simulation results indicate that the LED with an A1GaN/InGaN SL EBL has better optical performance than the LED with a conventional rectangular A1GaN EBL or a normal A1GaN/GaN SL EBL because of the appropriately modified energy band diagram, which is favorable ibr the injection of holes and confinement of elec- trons. Additionally, the efficiency droop of the LED with an AIGaN/InGaN SL EBL is markedly improved by reducing the polarization field in the active region. 展开更多
关键词 light-emitting diodes a1gan/Ingan superlattice efficiency droop numerical simulation
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The influence of AlGaN/GaN superlattices as electron blocking layers on the performance of blue InGaN light-emitting diodes
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作者 龚长春 范广涵 +5 位作者 张运炎 许毅钦 刘小平 郑树文 姚光锐 周德涛 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期579-582,共4页
P-A1GaN/P-GaN superlattices are investigated in blue InGaN light-emitting diodes as electron blocking layers. The simulation results show that efficiency droop is markedly improved due to two reasons: (i) enhanced ... P-A1GaN/P-GaN superlattices are investigated in blue InGaN light-emitting diodes as electron blocking layers. The simulation results show that efficiency droop is markedly improved due to two reasons: (i) enhanced hole concentration and hole carrier transport efficiency in A1GaN/GaN superlattices, and (ii) enhanced blocking of electron overflow between multiple quantum-wells and A1CaN/GaN superlattices. 展开更多
关键词 P-a1gan/P-gan superlattices numerical simulation emciency droop
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Al_xGa_(1-x)N/GaN调制掺杂异质结能带分裂特性
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作者 郑泽伟 沈波 +3 位作者 陈敦军 郑有炓 郭少令 褚君浩 《稀有金属》 EI CAS CSCD 北大核心 2004年第3期491-494,共4页
通过低温强磁场下的磁输运实验 ,研究了AlxGa1 -xN/GaN调制掺杂异质结构二维电子气 ( 2DEG)的能带分裂性质。1.4K温度下测量的磁阻曲线当磁场强度大于 5 .4T时观察到的明显对应于第一子带的自旋分裂现象。用Dingle作图法得到本样品τq ... 通过低温强磁场下的磁输运实验 ,研究了AlxGa1 -xN/GaN调制掺杂异质结构二维电子气 ( 2DEG)的能带分裂性质。1.4K温度下测量的磁阻曲线当磁场强度大于 5 .4T时观察到的明显对应于第一子带的自旋分裂现象。用Dingle作图法得到本样品τq 的大小为 0 17ps。结果表明 ,本实验所用的调制掺杂Al0 .2 2 Ga0 .78N/GaN异质结构具有较大的有效g因子g 。用高 2DEG浓度导致的交换相互作用加强解释了g 增强效应。在磁阻测量中改变磁场方向 ,自旋分裂现象表现出各向异性。用异质结构界面处强的极化电场解释了自旋分裂的各向异性。 展开更多
关键词 调制掺杂 AlxGa1-xN/gan异质结构 二维电子气 迁移率 有效g因子
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TriQuint的GaN/Si HEMT达到创纪录的功率水平
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《电子元器件应用》 2005年第2期34-34,共1页
TriQuint Semiconductor公司的研究人员宣布制造出世界上最大功率的Si衬底A1GaN/GaN HEMT。
关键词 HEMT a1gan/gan si衬底 Semiconductor公司 最大功率 制造 水平
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用MOVPE方法外延生长Si掺杂的立方相GaN(英文)
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作者 WU Jun ZHAO F H +3 位作者 Ito Y Yoshida S Onabe Shiraki Y 《发光学报》 EI CAS CSCD 北大核心 2001年第z1期1-4,共4页
用MOVPE方法采取一种两步生长过程生长了未掺杂和Si掺杂的GaN。在生长了一个 2 0nm厚的缓冲层后 ,外延生长了 1 μm厚的立方GaN外延层。利用二次离子质谱测定了掺杂的程度。
关键词 si掺杂gan MOVPE 光致发光特性
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用MOVPE方法外延生长Si掺杂的立方相GaN(英文)
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作者 WU Jun ZHAO F H +3 位作者 Ito Y Yoshida S Onabe Shiraki Y 《发光学报》 EI CAS CSCD 北大核心 2001年第S1期1-4,共4页
用MOVPE方法采取一种两步生长过程生长了未掺杂和Si掺杂的GaN。在生长了一个 2 0nm厚的缓冲层后 ,外延生长了 1 μm厚的立方GaN外延层。利用二次离子质谱测定了掺杂的程度。
关键词 si掺杂gan MOVPE 光致发光特性
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调制掺杂AlGaN/GaN异质结上的Pt肖特基接触
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作者 刘杰 沈波 +5 位作者 周玉刚 周慧梅 郑泽伟 张荣 施毅 郑有炓 《固体电子学研究与进展》 CAS CSCD 北大核心 2002年第4期381-384,共4页
研究了调制掺杂 Alx Ga1 - x N/Ga N表面 Pt肖特基接触的制备工艺 ,并对其进行了 I-V测量。通过改变对样品表面的处理工艺 ,研究了表面处理对调制掺杂 Alx Ga1 - x N/Ga N表面 Pt肖特基结接触特性的影响 ,在 n型掺杂浓度为 7.5× 1 ... 研究了调制掺杂 Alx Ga1 - x N/Ga N表面 Pt肖特基接触的制备工艺 ,并对其进行了 I-V测量。通过改变对样品表面的处理工艺 ,研究了表面处理对调制掺杂 Alx Ga1 - x N/Ga N表面 Pt肖特基结接触特性的影响 ,在 n型掺杂浓度为 7.5× 1 0 1 7cm- 3的 Al0 .2 2 Ga0 .78N样品表面 ,制备得到了势垒高度为 0 .94e V、理想因子为 1 .4的 Pt肖特基接触。这与国外报道的结果接近 (=1 .2 e V,n=1 .1 1 [1 ] ) 展开更多
关键词 调制掺杂 ALgan/gan异质结 肖特基接触 表面处理
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Optical and structural investigation of a-plane GaN layers on r-plane sapphire with nucleation layer optimization
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作者 张金风 许晟瑞 +1 位作者 张进成 郝跃 《Chinese Physics B》 SCIE EI CAS CSCD 2011年第5期409-412,共4页
Nonpolar a-plane GaN epilayers are grown on several r-plane sapphire substrates by metal organic chemical vapour deposition using different nucleation layers: (A) a CaN nucleation layer deposited at low temperature... Nonpolar a-plane GaN epilayers are grown on several r-plane sapphire substrates by metal organic chemical vapour deposition using different nucleation layers: (A) a CaN nucleation layer deposited at low temperature (LT); (B) an A1N nucleation layer deposited at high temperature; or (C) an LT thin AIN nucleation layer with an AIN layer and an A1N/A1CaN superlattice both subsequently deposited at high temperature. The samples have been characterized by Xray diffraction (XRD), atomic force microscopy and photoluminescence. The GaN layers grown using nucleation layers B and C show narrower XRD rocking curves than that using nucleation layer A, indicating a reduction in crystal defect density. Furthermore, the GaN layer grown using nucleation layer C exhibits a surface morphology with triangular defect pits eliminated completely. The improved optical property, corresponding to the enhanced crystal quality, is also confirmed by temperature-dependent and excitation power-dependent photoluminescence measurements. 展开更多
关键词 a-plane gan metal organic chemical vapour deposition a1N/a1gan superlattice PHOTOLUMINESCENCE
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Improved breakdown voltage of AlGaN/GaN HEMTs grown on Si substrates using partially Mg-doped GaN buffer layer by MOCVD 被引量:2
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作者 LAU KeiMay 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2010年第9期1578-1581,共4页
AlGaN/GaN high electron mobility transistors(HEMTs) were grown on Si substrates by MOCVD.In the HEMT structure,a 1 μm GaN buffer layer was partially doped with Mg in an attempt to increase the resistivity and minimiz... AlGaN/GaN high electron mobility transistors(HEMTs) were grown on Si substrates by MOCVD.In the HEMT structure,a 1 μm GaN buffer layer was partially doped with Mg in an attempt to increase the resistivity and minimize the buffer leakage.The AlGaN/GaN HEMTs grown on undoped and partially Mg-doped GaN buffer layers were processed and the DC characteristics of the devices were characterized for comparing the effect of Mg doping.For the device with the partially Mg-doped GaN buffer layer,a lower drain leakage current density of 55.8 nA/mm,a lower gate leakage current density of 2.73 μA/mm,and a higher off-state breakdown voltage of 104 V were achieved with device dimensions Lg/Wg/Lgs/Lgd=1/10/1/1 μm,better than the device with the undoped GaN buffer layer,which has a higher drain leakage current density of 9.2 μA/mm,a higher gate leakage current density of 91.8 μA/mm,and a lower off-state breakdown voltage of 87 V with the same device dimensions. 展开更多
关键词 ALgan/gan HEMT si substrate MOCVD BREAKDOWN voltage Mg-doped
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Stress,structural and electrical properties of Si-doped GaN film grown by MOCVD
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作者 许志豪 张进成 +4 位作者 段焕涛 张忠芬 朱庆玮 徐浩 郝跃 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2009年第12期13-17,共5页
The stresses, structural and electrical properties of n-type Si-doped GaN films grown by metaiorganic chemical vapor deposition (MOCVD) are systemically studied. It is suggested that the main stress relaxation is in... The stresses, structural and electrical properties of n-type Si-doped GaN films grown by metaiorganic chemical vapor deposition (MOCVD) are systemically studied. It is suggested that the main stress relaxation is induced by bending dislocations in low doping samples. But for higher doping samples, as the Si doping concentration increases, the in-plane stresses in the grown films are quickly relaxed due to the rapid increase of the edge dislocation densities. Hall effect measurements reveal that the carrier mobility first increases rapidly and then decreases with increasing Si doping concentration. This phenomenon is attributed to the interaction between various scattering process. It is suggested that the dominant scattering process is defect scattering for low doping samples and ionized impurity scattering for high doping samples. 展开更多
关键词 si-doped gan stress relaxation DEFECT electrical properties
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第一性原理研究Mg,Si和Mn共掺GaN 被引量:28
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作者 邢海英 范广涵 +1 位作者 章勇 赵德刚 《物理学报》 SCIE EI CAS CSCD 北大核心 2009年第1期450-458,共9页
采用基于密度泛函理论(DFT)的第一性原理平面波赝势法(PWP)计算Mg,Si和Mn共掺GaN电子结构和光学性质,分析比较计算结果.计算表明:掺杂后体系均在能隙深处产生自旋极化杂质带,具有半金属性,能产生自旋注入.与Mn掺杂GaN比较,Mg共掺后能使... 采用基于密度泛函理论(DFT)的第一性原理平面波赝势法(PWP)计算Mg,Si和Mn共掺GaN电子结构和光学性质,分析比较计算结果.计算表明:掺杂后体系均在能隙深处产生自旋极化杂质带,具有半金属性,能产生自旋注入.与Mn掺杂GaN比较,Mg共掺后能使居里温度(TC)升高,并在1.0eV出现源于Mn4+离子基态4T1(F)到4T2(F)态跃迁的较强的光吸收,而Mn掺杂GaN时位于1.3eV处的吸收峰消失;Si共掺后没能使TC升高,且在低能区无光吸收现象. 展开更多
关键词 Mg si和Mn共掺gan 电子结构 居里温度(TC) 光学性质
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δ掺杂对Si衬底GaN蓝光LED外延膜性能的影响研究 被引量:4
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作者 程海英 方文卿 +3 位作者 莫春兰 刘和初 王立 江风益 《光学学报》 EI CAS CSCD 北大核心 2006年第8期1269-1273,共5页
用X射线衍射方法通过不同晶面的ω扫描测试,分析了Si衬底GaN蓝光LED外延膜中n-型层δ掺杂Si处理对外延膜结晶性能的影响。报道了Si衬底GaN外延膜系列晶面的半峰全宽(FWHM)值。通过使用晶格旋转(Lattice-rotation)模型拟合,计算出样品的... 用X射线衍射方法通过不同晶面的ω扫描测试,分析了Si衬底GaN蓝光LED外延膜中n-型层δ掺杂Si处理对外延膜结晶性能的影响。报道了Si衬底GaN外延膜系列晶面的半峰全宽(FWHM)值。通过使用晶格旋转(Lattice-rotation)模型拟合,计算出样品的螺位错密度和刃位错密度。结果表明,δ掺杂Si处理后生长出的样品螺位错密度增大、刃位错密度减小,总位错密度有所减小。通过对未经δ掺杂处理和δ掺杂处理的GaN外延膜相应ω-2θ扫描半峰全宽值的比较,发现δ掺杂Si处理后生长出的样品非均匀应变较大;相应样品的LED电致发光光谱I、-V特性曲线显示δ掺杂后样品性能变好。 展开更多
关键词 薄膜光学 gan X射线衍射 si衬底 结晶性能 Δ掺杂
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p,n型掺杂剂与Mn共掺杂GaN的电磁性质 被引量:4
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作者 邢海英 范广涵 周天明 《物理学报》 SCIE EI CAS CSCD 北大核心 2009年第5期3324-3330,共7页
采用基于密度泛函理论的第一性原理平面波赝势法计算Mg,Zn,Si,O和Mn共掺GaN,分析比较共掺杂后的电子结构和磁学性质,并分别用平均场近似的海森伯模型和Zener理论估算共掺杂后体系的居里温度(TC).计算表明:共掺杂后体系均在能隙深处产生... 采用基于密度泛函理论的第一性原理平面波赝势法计算Mg,Zn,Si,O和Mn共掺GaN,分析比较共掺杂后的电子结构和磁学性质,并分别用平均场近似的海森伯模型和Zener理论估算共掺杂后体系的居里温度(TC).计算表明:共掺杂后体系均在能隙深处产生自旋极化杂质带,具有半金属性,能产生自旋注入.p型共掺杂(GaN:Mn-Mg\Zn)后体系具有较GaN:Mn更稳定的FM态且能使TC升高;而n型共掺杂(GaN:Mn-Si\O)后体系FM态稳定性和TC较GaN:Mn降低. 展开更多
关键词 Mg Zn si O和Mn共掺gan 第一性原理 居里温度(TC) 磁学性质
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RF Plasma MBE生长GaN材料及特性研究
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作者 李伟 赵智彪 +5 位作者 郑燕兰 李存才 杨全魁 胡建 齐鸣 李爱珍 《功能材料与器件学报》 CAS CSCD 1999年第3期219-223,共5页
用RFPlasma MBE方法生长出了GaN 材料,它的X 射线衍射半峰宽为335 秒,77K 下PL发光峰半峰宽为22meV,表明了材料具有较高的晶体质量。根据X射线衍射分析,位错密度约为7 .3 ×108cm -2 ... 用RFPlasma MBE方法生长出了GaN 材料,它的X 射线衍射半峰宽为335 秒,77K 下PL发光峰半峰宽为22meV,表明了材料具有较高的晶体质量。根据X射线衍射分析,位错密度约为7 .3 ×108cm -2 。用Si 作为掺杂剂,所得载流子浓度可覆盖1017 - 1019cm -3 的范围。掺Si GaN 的PL谱表明,Si 的引入可提高材料的发光效率。 展开更多
关键词 RFPlasmaMBE PL谱 硅掺杂 氧化镓
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掺杂GaN/AlN超晶格第一性原理计算研究 被引量:2
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作者 饶雪 王如志 +1 位作者 曹觉先 严辉 《物理学报》 SCIE EI CAS CSCD 北大核心 2015年第10期242-249,共8页
第一性原理计算方法在解释实验现象和预测新材料结构及其性质上有着重要作用.因此,通过基于密度泛函理论的第一性原理的方法,本文系统地研究了Mg和Si掺杂闪锌矿和纤锌矿两种晶体结构的GaN/AlN超晶格体系中的能量稳定性以及电学性质.结... 第一性原理计算方法在解释实验现象和预测新材料结构及其性质上有着重要作用.因此,通过基于密度泛函理论的第一性原理的方法,本文系统地研究了Mg和Si掺杂闪锌矿和纤锌矿两种晶体结构的GaN/AlN超晶格体系中的能量稳定性以及电学性质.结果表明:在势阱层(GaN层)中,掺杂原子在体系中的掺杂形成能不随掺杂位置的变化而发生变化,在势垒层(Al N层)中也是类似的情况,这表明对于掺杂原子来说,替代势垒层(或势阱层)中的任意阳离子都是等同的;然而,相比势阱层和势垒层的掺杂形成能却有很大的不同,并且势阱层的掺杂形成能远低于势垒层的掺杂形成能,即掺杂元素(MgGa,MgAl,SiGa和SiAl)在势阱区域的形成能更低,这表明杂质原子更易掺杂于结构的势阱层中.此外,闪锌矿更低的形成能表明:闪锌矿结构的超晶格体系比纤锌矿结构的超晶格体系更易于实现掺杂;其中,闪锌矿结构中,负的形成能表明:当Mg原子掺入闪锌矿结构的势阱层中会自发引起缺陷.由此,制备以闪锌矿结构超晶格体系为基底的p型半导体超晶格比制备n型半导体超晶格需要的能量更低并且更为容易制备.对于纤锌矿体系来说,制备p型和n型半导体的难易程度基本相同.电子态密度对掺杂体系的稳定性和电学性质进一步分析发现,掺杂均使得体系的带隙减小,掺杂前后仍然为第一类半导体.综上所述,本文内容为当前实验中关于纤锌矿结构难以实现p型掺杂问题提供了一种新的技术思路,即可通过调控相结构实现其p型掺杂. 展开更多
关键词 gan/AlN超晶格 第一性原理 si和Mg掺杂 电子态密度
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