共查询到17条相似文献,搜索用时 718 毫秒
1.
对蓝宝石衬底上的InGaN/GaN和InGaN/AlGaN多量子阱结构和经激光剥离去除衬底的InGaN/GaN和InGaN/AlGaN多量子阱结构薄膜样品,进行了光致发光谱、高分辨XRD和喇曼光谱测量.PL测量结果表明,相对于带有蓝宝石衬底的样品,InGaN/GaN多量子阱薄膜样品的PL谱峰值波长发生较小的蓝移,而InGaN/AlGaN多量子阱薄膜样品的PL谱峰值波长发生明显的红移;喇曼光谱的结果表明,激光剥离前后E2模的峰值从569.1减少到567.5cm-1.这说明激光剥离去除衬底使得外延层整体的压应力得到部分释放,但InGaN/GaN与InGaN/AlGaN多量子阱结构中阱层InGaN的应力发生了不同的变化.XRD的结果证实了这一结论. 相似文献
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对蓝宝石衬底上的InGaN/GaN和InGaN/AlGaN多量子阱结构和经激光剥离去除衬底的InGaN/GaN和InGaN/AlGaN多量子阱结构薄膜样品,进行了光致发光谱、高分辨XRD和喇曼光谱测量. PL测量结果表明,相对于带有蓝宝石衬底的样品,InGaN/GaN多量子阱薄膜样品的PL谱峰值波长发生较小的蓝移,而InGaN/AlGaN多量子阱薄膜样品的PL谱峰值波长发生明显的红移;喇曼光谱的结果表明,激光剥离前后E2模的峰值从569.1减少到567.5cm-1. 这说明激光剥离去除衬底使得外延层整体的压应力得到部分释放,但InGaN/GaN与InGaN/AlGaN多量子阱结构中阱层InGaN的应力发生了不同的变化. XRD的结果证实了这一结论. 相似文献
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生长温度对InGaN/GaN多量子阱LED光学特性的影响 总被引:1,自引:0,他引:1
利用低压MOCVD系统,在蓝宝石衬底上外延生长了InGaN/GaN多量子阱蓝紫光LED结构材料.研究了生长温度对有源层InGaN/GaN多量子阱的合金组分、结晶品质及其发光特性的影响.结果表明当生长温度从730℃升到800℃时,LED的光致发光波长从490nm移到380nm,室温下PL谱发光峰的半高全宽从133meV降到73meV,表明了量子阱结晶性的提高.高温生长时,PL谱中还观察到了GaN的蓝带发光峰,说明量子阱对载流子的限制作用有所减弱.研究表明,通过改变生长温度可以对LED发光波长及有源层InGaN的晶体质量实现良好的控制. 相似文献
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利用波长为248nm的KrF准分子激光器进行了蓝宝石衬底GaN外延层剥离。对极薄的MOCVD生长的单层GaN外延膜(3μm)和InGaNLD外延膜(5μm)实现了大面积剥离。对剥离蓝宝石衬底背面抛光和未抛光外延片的不同特点作了比较,激光剥离所需的能量密度阈值分别约为200mJ/cm2和300mJ/cm2,优化结果表明,能量密度分别在400mJ/cm2和600mJ/cm2可实现稳定的剥离。同时对剥离后的InGaN多量子阱LD结构薄膜进行了解理,SEM观察显示获得的InGaNLD腔面平整光滑。基于这种技术可以获得无蓝宝石衬底的GaN基光电子和电子器件。 相似文献
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垂直电极结构GaN基发光二极管的研制 总被引:1,自引:0,他引:1
利用激光剥离技术(LLO)和晶片键合技术将GaN基发光二极管(LED)薄膜与蓝宝石衬底分离并转移到Si衬底上,高分辨X射线衍射(HRXRD)和阴极荧光谱(CL)结果表明激光剥离过程没有影响GaN量子阱的结构和光学性质,GaN和InGaN/GaN多量子阱的发光峰都呈现红移,这都来源于去除蓝宝石后薄膜中应力的释放.采用金属In和Pd的合金化键合过程解决了GaN材料与Si衬底的结合问题,结合逐个芯片剥离和键合的方式实现了GaN大面积均匀转移.成功研制了激光剥离垂直电极结构的GaN基LED,L-I测试特性表明器件的热饱和电流和出光功率都有很大的提高. 相似文献
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利用激光剥离技术(LLO)和晶片键合技术将GaN基发光二极管(LED)薄膜与蓝宝石衬底分离并转移到Si衬底上,高分辨X射线衍射(HRXRD)和阴极荧光谱(CL)结果表明激光剥离过程没有影响GaN量子阱的结构和光学性质,GaN和InGaN/GaN多量子阱的发光峰都呈现红移,这都来源于去除蓝宝石后薄膜中应力的释放.采用金属In和Pd的合金化键合过程解决了GaN材料与Si衬底的结合问题,结合逐个芯片剥离和键合的方式实现了GaN大面积均匀转移.成功研制了激光剥离垂直电极结构的GaN基LED,L-I测试特性表明器件的热饱和电流和出光功率都有很大的提高. 相似文献
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采用低压金属有机化学沉积方法制备了InGaN/GaN多量子阱.变温PL测量发现,量子阱发光强度具有良好的温度稳定性,随着温度升高(10~300K),发光强度只减小到1/3左右.分析认为,InGaN/GaN多量子阱的多峰发光结构是由多量子阱的组分及阱宽的不均匀引起的.随着温度升高,GaN带边及量子阱的光致发光均向低能方向移动,但与GaN带边不同,量子阱发光峰值变化并不与通过内插法得到的Varshni经验公式相吻合,而是与InN带边红移趋势一致,分析了导致这种现象的可能因素.还分析了量子阱发光寿命随温度升高而减小的原因. 相似文献
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利用MOCVD系统在Al2O3衬底上生长InGaN材料和InGaN/GaN量子阱结构材料,研究发现InGaN材料中In组份几乎不受TMG与TMI的流量比的影响,而只与生长温度有关,生长温度由800℃降低到740℃,In组份的从0.22增加到0.45;室温InGaN光致发光光谱(PL)峰全半高宽(FWHM)为15.5nm;InGaN/GaN量子阱区InGaN的厚度2nm,但光荧光的强度与100nm厚InGaN的体材料相当。 相似文献
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We report an AlGaN/GaN/InGaN/GaN double heterojunction high electron mobility transistors (DH-HEMTs) with high-mobility two-dimensional electron gas (2-DEG) and reduced buffer leakage. The device features a 3-nm thin In/sub x/Ga/sub 1-x/N(x=0.1) layer inserted into the conventional AlGaN/GaN HEMT structure. Assisted by the InGaN layers polarization field that is opposite to that in the AlGaN layer, an additional potential barrier is introduced between the 2-DEG channel and buffer, leading to enhanced carrier confinement and improved buffer isolation. For a sample grown on sapphire substrate with MOCVD-grown GaN buffer, a 2-DEG mobility of around 1300 cm/sup 2//V/spl middot/s and a sheet resistance of 420 /spl Omega//sq were obtained on this new DH-HEMT structure at room temperature. A peak transconductance of 230 mS/mm, a peak current gain cutoff frequency (f/sub T/) of 14.5 GHz, and a peak power gain cutoff frequency (f/sub max/) of 45.4 GHz were achieved on a 1/spl times/100 /spl mu/m device. The off-state source-drain leakage current is as low as /spl sim/5 /spl mu/ A/mm at V/sub DS/=10 V. For the devices on sapphire substrate, maximum power density of 3.4 W/mm and PAE of 41% were obtained at 2 GHz. 相似文献
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L. W. Wu S. J. Chang Y. K. Su T. Y. Tsai T. C. Wen C. H. Kuo W. C. Lai J. K. Sheu J. M. Tsai S. C. Chen B. R. Huang 《Journal of Electronic Materials》2003,32(5):411-414
Nitride-based light-emitting diodes (LEDs) with Si-doped n+-In0.23Ga0.77N/GaN short-period superlattice (SPS) tunneling contact top layer were fabricated. It was found that although the measured
specific-contact resistance is around 1 × 10−2 Ω-cm2 for samples with an SPS tunneling contact layer, the measured specific-contact resistance is around 1.5×100 Ω-cm2 for samples without an SPS tunneling contact layer. Furthermore, it was found that one could lower the LED-operation voltage
from 3.75 V to 3.4 V by introducing the SPS structure. It was also found that the LED-operation voltage is almost independent
of the CP2Mg flow rate when we grow the underneath p-type GaN layer. The LED-output intensity was also found to be larger for samples
with the SPS structure. 相似文献
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I. L. Krestnikov A. V. Sakharov W. V. Lundin Yu. G. Musikhin A. P. Kartashova A. S. Usikov A. F. Tsatsul’nikov N. N. Ledentsov Zh. I. Alferov I. P. Soshnikov E. Hahn B. Neubauer A. Rosenauer D. Litvinov D. Gerthsen A. C. Plaut A. A. Hoffmann D. Bimberg 《Semiconductors》2000,34(4):481-487
InGaN/GaN structures with dense arrays of InGaN nanodomains were grown by metallorganic chemical vapor deposition. Lasing in vertical direction occurs at low temperatures, indicating ultrahigh gains (~ 105 cm?1) in the active region. Fabrication of an effective AlGaN/GaN distributed Bragg reflector with reflectivity exceeding 90% enables vertical lasing at room temperature in structures with a bottom distributed Bragg reflector, despite the absence of a well-reflecting upper mirror. The lasing wavelength is 401 nm, and the threshold excitation density is 400 kW/cm2. 相似文献
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Wang Xingyu Wang Peng Yin Hongjie Zhou Guofu Nötzel Richard 《Journal of Electronic Materials》2020,49(6):3577-3582
Journal of Electronic Materials - We introduce a diode that operates differently from p–n junction or Schottky diodes. It is based on a p-Si/n-In0.4Ga0.6N heterojunction with a SiNx... 相似文献
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设计了InGaN/GaN超晶格垒层替代p-GaN和n-GaN附近传统GaN垒层的InGaN/GaN多量子阱(MQW)发光二极管(LEDs)结构。通过数值方法模拟出两种LED结构的光功率-电压(L-V)曲线、电致发光(EL)谱、能带图、电子浓度分布和辐射复合速率。结果表明InGaN/GaN超晶格替代n-GaN附近GaN垒层的LED结构比替代p-GaN附近GaN垒层的LED显示出更高的发光强度。这种发光增强的原因是InGaN/GaN超晶格替代n-GaN附近GaN垒层可以提高电子注入效率和辐射复合速率。 相似文献
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Adivarahan V. Gaevski M. Koudymov A. Yang J. Simin G. Khan M. A. 《Electron Device Letters, IEEE》2007,28(3):192-194
We describe a novel AlGaN/InGaN/GaN metal-oxide-semiconductor double heterostructure field-effect transistor with peak drain current of 1.67 A/mm and 2-GHz RF power of 15 W/mm at a drain bias as low as 35 V. These high values of peak currents and high RF powers at relatively low drain bias resulted from an additional selective area doping of the access regions during the device fabrication. The RF-output power of 12.5 W/mm (at a drain bias of VD=30 V) was stable within a 0.5-dB variations during a 100-h continuous-wave stress test 相似文献