共查询到18条相似文献,搜索用时 143 毫秒
1.
利用深能级瞬态谱(DLTS)、傅里叶变换红外光谱(FT-IR)对GaN以及GaN掺Er/Pr的样品进行了 电学和光学特性分析.研究发现未掺杂的GaN样品只在导带下0.270eV处有一个深能级;GaN注 入Er经900℃,30min退火后的样品出现了四个深能级,能级位置位于导带下0.300 eV,0.188 eV,0.600 eV 和0.410 eV;GaN注入Pr经1050℃,30min退火后的样品同样出现了四个深能级 ,能级位置位于导带下0.280 eV,0.190 eV,0.610 eV 和0.390 eV;对每一个深能级的来源 进行了讨论.光谱研究表明,掺Er的GaN样品经900℃,30min退火后,可以观察到Er的1538nm 处的发光,而且对能量输运和发光过程进行了讨论.
关键词:
GaN
Er
Pr
深能级 相似文献
2.
高浓度Er/Yb共掺ZnO薄膜的结构及室温光致发光特性 总被引:3,自引:0,他引:3
采用射频磁控溅射方法制备了Er/Yb共掺ZnO薄膜,研究了退火处理对高浓度Er/Yb共掺ZnO薄膜的结构演化和光致发光(PL)特性的影响。X射线衍射分析结果表明:Er/Yb掺杂导致ZnO薄膜的晶粒细化及择优取向性消失,ZnO晶粒随退火温度的增加而逐渐长大。900℃退火时,出现Er3 、Yb3 偏析,退火温度高于1000℃时,薄膜与基体间发生了界面反应,1200℃时,ZnO完全转变为Zn2SiO4相。光致发光测量结果表明:高于900℃退火处理后,Er/Yb共掺ZnO薄膜在1540 nm附近具有明显的光致发光,发光强度在退火温度为1050℃时达到最大值;光致发光光谱呈现典型的晶体基质中Er3 离子发光光谱所具有的明锐多峰结构特征。此外,探讨了薄膜结构演化及其对光致发光光谱的影响。 相似文献
3.
用射频反应溅射法在Si(111)衬底上制备了C轴取向的多晶ZnO薄膜,通过不同温度的退火处理,研究了退火对多晶ZnO薄膜结构和发光特性的影响.由x射线衍射得知,随退火温度的升高,晶粒逐渐变大,薄膜中压应力由大变小至出现张应力.光致发光测量发现,样品在430nm附近有一光致发光峰, 峰的强度随退火温度升高而减弱,联合样品电阻率随退火温度升高而逐渐变大的测量及能级图,推测出ZnO薄膜中的蓝光发射主要来源于锌填隙原子缺陷能级与价带顶能级间的跃迁.
关键词:
ZnO薄膜
退火
光致发光
射频反应溅射 相似文献
4.
室温下利用磁控溅射在p型Si(111)衬底上沉积了Cu薄膜. 利用X射线衍射和卢瑟福背散射分别对未退火以及在不同温度点退火后样品的结构进行了表征. 在此基础上,研究了Cu/SiO2/Si(111)体系的扩散和界面反应. 实验结果表明:当退火温度高于450℃时出现明显的扩散现象,并且随着温度的升高,体系扩散现象会更加显著. 当退火温度低于450℃时没有铜硅化合物生成,当温度达到500℃时才有铜硅化合物生成.
关键词:
薄膜
扩散
界面反应
硅化物 相似文献
5.
利用背散射/沟道(RBS/C)技术、原子力显微镜(AFM)和光致发光(PL)谱研究了掺镨GaN薄膜的微结构和可见光发光特性。RBS/C结果表明,注入Pr后,在注入层引入了晶格损伤;注入样品经1050℃退火后,部分损伤得到恢复,但是晶体质量没有恢复到注入前的状态。AFM结果表明,注入Pr后,表面凹凸不平,而且在注入区引起了膨胀,膨胀幅度达到23.368nm左右。PL结果表明,在850—1050℃退火,发光强度按e指数增加;当退火温度达到1050℃,发光强度最强,经过数据拟合可得Pr^3+的热激活能为5.8eV。 相似文献
6.
采用反应射频磁控溅射法在 Si(100)基片上制备了高c轴择优取向的ZnO薄膜,研究了退火温度对ZnO薄膜的晶粒尺度、应力状态、成分和发光光谱的影响,探讨了ZnO薄膜的紫外发光光谱和可见发光光谱与薄膜的微观状态之间的关系.研究结果显示,在600—1000℃退火温度范围内,退火对薄膜的织构取向的影响较小,但薄膜的应力状态和成分有比较明显的变化.室温下光致发光光谱分析发现,薄膜的近紫外光谱特征与薄膜的晶粒尺度和缺陷状态之间存在着明显的对应关系;而近紫外光谱随退火温度升高所呈现的整体峰位红移是各激子峰相对比例变
关键词:
ZnO薄膜
退火
光致发光
射频反应磁控溅射
可见光发射 相似文献
7.
采用金属有机化学气相沉积(MOCVD)技术以蓝宝石为衬底在n型GaN单晶层上生长了InGaN/GaN多量子阱结构外延薄膜,利用高分辨X射线衍射(HRXRD),卢瑟福背散射/沟道(RBS/channeling),以及光致发光(PL)技术对InGaN/GaN多量子阱结构薄膜分别进行了平均晶格常数计算、In原子替位率计算和In组分的定量分析.研究表明:InGaN/GaN多量子阱的水平和垂直方向平均晶格常数分别为aepi=0.3195nm,cepi=0.5198nm,In原子的替位率为99.3%,利用HRXRD和RBS/channeling两种分析技术计算In的组分分别是0.023和0.026,并与样品生长时设定的预期目标相符合,验证了两种实验方法的准确性;而用室温条件下的光致发光谱(PL)来计算InGaN/GaN多量子阱中In的组分是与HRXRD和RBS/channeling的实验结果相差很大,说明用PL测试In组分的方法是不适宜的.
关键词:
InGaN/GaN多量子阱
高分辨X射线衍射
卢瑟福背散射/沟道
光致发光 相似文献
8.
采用等离子体增强化学气相沉积法, 以NH3与SiH4为反应气体, n型单晶硅为衬底, 低温(220 ℃)沉积了富硅氮化硅(SiNx)薄膜. 在N2氛围中, 于500–1100 ℃ 范围内对样品进行了热退火处理. 采用Raman 光谱技术分析了薄膜内硅量子点的结晶情况, 结果表明, 当退火温度低于950 ℃时, 样品的晶化率低于18%, 而当退火温度升为1100 ℃, 晶化率增加至53%, 说明大部分硅量子点都由非晶态转变为晶态. 实验通过Fourier 变换红外吸收(FTIR)光谱检测了样品中各键的键合结构演变, 发现Si–N键和Si–H键随退火温度升高向高波数方向移动, 说明了薄膜内近化学计量比的氮化硅逐渐形成. 实验还通过光致发光(PL)光谱分析了各样品的发光特性, 发现各样品中均有5个发光峰, 讨论了它们的发光来源, 结合Raman光谱与FTIR光谱表明波长位于500–560 nm的绿光来源于硅量子点, 其他峰则来源于薄膜内的缺陷态. 研究了硅量子点的分布和尺寸对发光带移动的影响, 并根据PL峰位计算了硅量子点的尺寸, 其大小为1.6–3 nm, 具有良好的限域效应. 这些结果有助于制备尺寸不同的硅量子点和基于硅量子点光电器件的实现.
关键词:
硅量子点
氮化硅薄膜
光致发光
Fourier 变换红外吸收 相似文献
9.
以草酸为电解液,采用二次阳极氧化法制备出了纳米多孔氧化铝薄膜,经不同退火温度和退火气氛处理氧化铝薄膜后,通过分析其光致发光光谱得出:相同的退火气氛中, 退火温度T≤600 ℃ 时,T=500 ℃具有最大的光致发光强度;退火温度T≥700 ℃时,随着退火温度的升高,样品的发光强度增大。在不同的退火气氛中,多孔氧化铝薄膜随着退火温度的升高,发光峰位改变不同,即在空气中退火处理后,随着退火温度的升高,发光峰位蓝移,而在真空中退火处理后,发光峰位并不随退火温度的升高而变化;通过对1 100 ℃高温退火处理后的氧化铝薄膜的光致发光曲线的高斯拟合,可以看出,经退火处理后的多孔氧化铝,主要存在三个发光中心,发光曲线在350~600 nm范围内对应三个发射峰, 发射波长分别为387,410,439 nm。相同的退火温度下,空气中退火得到的氧化铝薄膜的光致发光强度大于真空中退火处理后的氧化铝薄膜。基于实验结果,结合X射线色散能谱(EDS)、红外反射光谱等表征手段,探讨了多孔氧化铝薄膜的发光机制,并对经过不同退火条件得到的多孔氧化铝薄膜的光致发光特性的改变做出了合理的解释。 相似文献
10.
在蓝宝石衬底上通过金属有机物化学气相沉积(metal-organic chemical vapor deposition,MOCVD)方法外延生长的GaN薄膜具有良好的结晶品质,χmin达到2.00%. 结合卢瑟福背散射/沟道(Rutherford backscattering/channeling,RBS/C)和高分辨X射线衍射(high-resolution X-ray diffraction,HXRD)的实验测量,研究了不同剂量和不同角度Mg+注入GaN所造成的辐射损伤. 实验结果表明,随注入剂量的增大,晶体的辐射损伤也增大,注入剂量在1×1015atom/cm2以下,χmin小于4.78%,1×1016atom/cm2是Mg+注入GaN的剂量阈值,超过这个阈值,结晶品质急剧变差,χmin达到29.5%;随机注入比沟道注入的辐射损伤大,且在一定范围内随注入角度的增大,损伤也增大,在4×1015atom/cm2剂量下偏离〈0001〉沟道0°,4°,6°,9°时的χmin(%)分别为6.28,8.46,10.06,10.85;经过700℃/10min+1050℃/20s两步退火和1000℃/30s高温快速退火后,晶体的辐射损伤都有一定程度的恢复,而且1000℃/30s高温快速退火的效果更好,晶体的辐射损伤可以得到更好的恢复.
关键词:
GaN
卢瑟福被散射/沟道
高分辨X射线衍射
辐射损伤 相似文献
11.
12.
Shoubin Xue Xing Zhang Ru Huang Huizhao Zhuang 《Applied Physics A: Materials Science & Processing》2009,94(2):287-291
ZnO thin films were first prepared on Si(111) substrates using a radio frequency magnetron sputtering system. Then the as-grown
ZnO films were annealed in oxygen ambient at temperatures of 700, 800, 900, and 1000°C , respectively. The morphologies of
ZnO films were studied by an atom force microscope (AFM). Subsequently, GaN epilayers about 500 nm thick were deposited on
the ZnO buffer layers. The GaN/ZnO films were annealed in NH3 ambient at 900°C. The microstructure, morphology and optical properties of GaN films were studied by x-ray diffraction (XRD),
AFM, scanning electron microscopy (SEM) and photoluminescence (PL). The results are shown, their properties having been investigated
particularly as a function of the ZnO layers. For better growth of the GaN films, the optimal annealing temperature of the
ZnO buffer layers was 900°C. 相似文献
13.
The photoluminescence (PL) properties of Eu-implanted GaN thin films are studied. The experimental results show that the PL intensity is seriously affected by ion implantation conditions. The PL efficiency increases exponentially with annealing temperature increasing up to a maximum
temperature of 1050℃. Moreover, the PL intensity for the sample implanted along the channelling direction is nearly twice more than that observed from the sample implanted along the random direction. The thermal quenching of PL intensity from 10K to 300K for sample annealed at
1050℃ is only 42.7%. 相似文献
14.
Effects of high-dose Ge ion implantation and post-implantation annealing on ZnO thin films 下载免费PDF全文
This paper reports that ion implantation to a dose of 1×1017
ions/cm2 was performed on c-axis-orientated ZnO thin films deposited on
(0001) sapphire substrates by the sol-gel technique. After ion implantation,
the as-implanted ZnO films were annealed in argon ambient at different
temperatures from 600-900℃. The effects of ion implantation
and post-implantation annealing on the structural and optical properties of
the ZnO films were investigated by x-ray diffraction (XRD),
photoluminescence (PL). It was found that the intensities of (002) peak and
near band edge (NBE) exitonic ultraviolet emission increased with increasing
annealing temperature from 600-900℃. The defect related deep
level emission (DLE) firstly increased with increasing annealing temperature
from 600- 750℃, and then decreased quickly with increasing
annealing temperature. The recovery of the intensities of NBE and DLE occurs
at \sim 850℃ and \sim 750℃ respectively. The relative
PL intensity ratio of NBE to DLE showed that the quality of ZnO films
increased continuously with increasing annealing temperature from 600 -
900℃. 相似文献
15.
Annealing effect on structure and green emission of ZnO nanopowder by decomposing precursors 下载免费PDF全文
ZnO nanopowder is successfully synthesized by annealing
the precursors in oxygen gas using the chemical precipitation method.
Structural and optical properties of thus synthesized ZnO nanopowder
are characterized by scanning electron microscopy (SEM) and
photoluminescence (PL). The morphology of ZnO nanopowders evolves
from nanorod to cobble as annealing temperature increases from 500
to 1000~\du, while spiral structures are observed in the samples
annealed at 900 and 1000~\du. The PL spectra of ZnO nanopowder
consist of largely green and yellow emission bands. The green
emission from ZnO nanopowder depends strongly on the annealing
temperature with a peak intensity at a temperature lower than 800~℃
while the yellow emission is associated with interstitial oxygen
\rm O_\i. 相似文献
16.
采用脉冲激光沉积技术在Si/蓝宝石衬底上制备了ZnO薄膜,结合快速退火设备研究了不同退火温度(500~900℃)及退火气氛(N2,O2)对薄膜的结构及其发光性能的影响。并优化条件得到具有最小半峰全宽及最大晶粒尺寸的薄膜。X射线衍射(XRD)结果表明:氮气氛下退火的ZnO薄膜最佳退火温度为900℃;氧气氛下退火的ZnO薄膜最佳退火温度为800℃。红外(IR)光谱中,退火后Zn-O特征振动峰红移,说明在退火过程中,原子重新排布后占据较低能量位置;同样的退火温度下,氮气氛下退火的薄膜质量更优。同步辐射光电子能谱(synchrotron-based XPS)分别表征了未退火及N2,O2下900℃退火的ZnO薄膜,分峰拟合结果表明氧气氛下退火产生更多的氧空位。结构表征结合光致发光(PL)谱表明绿光的发光峰与氧空位有关。 相似文献
17.
采用等离子体化学气相沉积技术制备氢化非晶硅薄膜,经过不同温度下的热退火处理,使薄膜由非晶结构向晶化结构转变,得到含有纳米晶粒的晶化硅薄膜.在晶化过程中,采用Raman技术对样品的结构进行表征.通过变温电导率的测试,对薄膜的电学输运性质进行了分析.研究结果表明:退火温度为700 ℃时,样品中开始有纳米晶形成,随着退火温度的增加,样品的晶化比增大,在1000 ℃时,薄膜的晶化比达到90%以上.在700 ℃退火时,薄膜中晶化成分较低,载流子的传输特性主要受到与硅悬挂键有关的缺陷态影响,表现为带尾定域态的跳跃电导
关键词:
氢化非晶硅
退火
纳米硅
电输运 相似文献
18.
T. Shimada Y. Shiraki K.F. Komatsubara 《Journal of Physics and Chemistry of Solids》1976,37(3):315-319
Backscattering yields of 1.5 MeV?He+ ions and low temperature photoluminescence (PL) spectra were measured in GaP crystals implanted with 200 keV?N+ ions as functions of ion-dose, temperature during implantation and annealing temperature after implantation. Backscattering results indicate that hot implantation at 500°C greatly reduces radiation damage. The PL intensities of NN lines become maximum in the sample implanted with N+ ions of 3 × 1014cm?2 at 500°C, and annealed at 1000°C for 1 hr with aluminum glass. The PL intensity is comparable to that of the nitrogen-doped sample during liquid phase epitaxy which is widely accepted as the best method of introducing nitrogen into GaP crystals. In the case of 500°C—hot implantation, the radiation damage produced during implantation is annealed out at 700 ~ 800°C and the implanted nitrogen substitutes for the phosphorous sites after annealing at 900 ~ 1000°C. Some kinds of defects or strains remain around the NN centers even in implanted samples with a maximum PL efficiency. These defects or strains don't seem to reduce the PL efficiency. In the case of room temperature implantation, PL efficiency decreases to one-hundredth or one-thousandth due to the formation of the non-crystalline state compared with hot implantation. 相似文献