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1.
MOCVD制备用于薄膜太阳电池的ZnO薄膜研究 总被引:2,自引:11,他引:2
利用金属有机物化学气相沉积(MOCVD)生长技术,采用二乙基锌(DEZ)作Zn源和H2O作O源,使用B2H6 为掺杂气体,制备出了光电特性稳定的低电阻率、高透过率的ZnO薄膜。制备条件为:衬底温度160 ℃,DEZ的流量为342μmol/min,H2O流量为500μmol/min,反应气压为5×133.32 Pa,B2H6 流量为5 sccm,掺杂手段为气体掺杂。在薄膜面积为10 cm×10 cm、厚度为550 nm时,方块电阻为40Ω/□。透过率>85%。 相似文献
2.
CdTe solar cells were fabricated by depositing CdTe films on CdS/SnO2/glass substrates in various metalorganic chemical vapor deposition growth ambient with varying Te/Cd mole ratio in the range
of 0.02 to 15. The short-circuit current density (Jsc) showed a minimum at a Te/Cd ratio of 0.1 and increased on both sides of this minimum. The open-circuit voltage (Voc) was found to be the highest for the Te-rich growth ambient (Te/Cd∼6)and was appreciably lower (600 mV as opposed to 720
mV) for the stoichiometric and the Cd-rich growth conditions. This pattern resulted in highest cell efficiency (12%) on Te-rich
CdTe films. Auger electron spectroscopy revealed a high degree of atomic interdiffusion at the CdS/CdTe interface when the
CdTe films were grown in the Te-rich conditions. It was found that the current transport in the cells grown in the Cd-rich
ambient was controlled by the tunneling/interface recombination mechanism, but the depletion region recombination became dominant
in the Te-rich cells. These observations suggest that the enhanced interdiffusion reduces interface states due to stress reduction
or to the gradual transition from CdS to CdTe. The hypothesis of reduced defect density in the CdTe cells grown in the Te-rich
conditions is further supported by the high effective lifetime, measured by time-resolved photoluminescence, and the reduced
sensitivity of quantum efficiency to forward/light bias. 相似文献
3.
MOCVD法制备磷掺杂p型ZnO薄膜 总被引:1,自引:0,他引:1
利用金属有机化学气相沉积方法在玻璃衬底上生长了掺磷的p型ZnO薄膜.实验采用二乙基锌作为锌源,高纯氧气和五氧化二磷粉末分别作为氧源及磷掺杂源.实验表明:生长温度为400~450℃时获得了p型ZnO薄膜,而且在420℃时,其电学性能最好,空穴浓度为1.61×1018cm-3,电阻率为4.64Ω·cm,迁移率为0.838cm2/(V·s).霍尔测试和低温光致发光谱证实了该ZnO薄膜的p型导电特性,并观察到薄膜位于3.354eV与中性受主束缚激子相关的发射峰. 相似文献
4.
MOCVD法制备磷掺杂p型ZnO薄膜 总被引:6,自引:1,他引:6
利用金属有机化学气相沉积方法在玻璃衬底上生长了掺磷的p型ZnO薄膜.实验采用二乙基锌作为锌源,高纯氧气和五氧化二磷粉末分别作为氧源及磷掺杂源.实验表明:生长温度为400~450℃时获得了p型ZnO薄膜,而且在420℃时,其电学性能最好,空穴浓度为1.61×1018cm-3,电阻率为4.64Ω·cm,迁移率为0.838cm2/(V·s).霍尔测试和低温光致发光谱证实了该ZnO薄膜的p型导电特性,并观察到薄膜位于3.354eV与中性受主束缚激子相关的发射峰. 相似文献
5.
Based on the physical vapor transport (PVT) method, the growth of large-size CdS crystals inside a vertical semi-closed tube is studied. Firstly, in order to ensure 1D diffusion-advection transport, multi-thin tubes are used in the growth tube. The XRD spectra of the CdS crystal grown in this configuration indicates that the crystal quality has clearly been improved, where the FWHM is 58.5 arcsec. Secondly, theoretical and experimental growth rates under different total pressures are compared; the results show that the experiential growth rate equation is valid for our semi-tube growth, and it could be used to estimate the growth rate and maximum growth time under different total pressures. 相似文献
6.
Based on the physical vapor transport (PVT) method, the growth of large-size CdS crystals inside a vertical semi-closed tube is studied. Firstly, in order to ensure 1D diffusion-advection transport, multi-thin tubes are used in the growth tube. The XRD spectra of the CdS crystal grown in this configuration indicates that the crystal quality has clearly been improved, where the FWHM is 58.5 arcsec. Secondly, theoretical and experimental growth rates under different total pressures are compared; the results show that the experiential growth rate equation is valid for our semi-tube growth, and it could be used to estimate the growth rate and maximum growth time under different total pressures. 相似文献
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采用二乙基锌(DEZn)和水(H2O)作为生长源,利用金属有机化学气相沉积(MOCVD)的方法,在100~400℃低温范围内,在GaAs(001)衬底上制备了ZnO薄膜.利用X射线衍射(XRD),室温PL,AFM,SEM研究了薄膜的晶体结构特性、发光特性及表面形貌特性.XRD分析表明ZnO薄膜具有很强的c轴取向,(002)峰的FWHM平均值为0.3°.当生长温度达到400℃时从SEM测量结果可以观察到薄膜表面呈六角状结晶.随着生长温度的升高,薄膜的晶粒尺寸变大,结晶质量得到提高但同时表面变粗糙.室温PL测量显示薄膜在370nm附近有强的近带边发射,没有观测到深能级发射峰. 相似文献
9.
采用二乙基锌(DEZn)和水(H2O)作为生长源,利用金属有机化学气相沉积(MOCVD)的方法,在100~400℃低温范围内,在GaAs(001)衬底上制备了ZnO薄膜.利用X射线衍射(XRD),室温PL,AFM,SEM研究了薄膜的晶体结构特性、发光特性及表面形貌特性.XRD分析表明ZnO薄膜具有很强的c轴取向,(002)峰的FWHM平均值为0.3°.当生长温度达到400℃时从SEM测量结果可以观察到薄膜表面呈六角状结晶.随着生长温度的升高,薄膜的晶粒尺寸变大,结晶质量得到提高但同时表面变粗糙.室温PL测量显示薄膜在370nm附近有强的近带边发射,没有观测到深能级发射峰. 相似文献
10.
A. M. Jones M. L. Osowski R. M. Lammert J. A. Dantzig J. J. Coleman 《Journal of Electronic Materials》1995,24(11):1631-1636
A computational diffusion model is used to predict thickness and composition profiles of ternary InxGa1-xAs quantum wells grown by selective-area, atmospheric pressure metalorganic chemical vapor deposition (MOCVD), and its accuracy
is investigated. The model utilizes diffusion equations and boundary conditions derived from basic MOCVD theory, with reaction
parameters derived from experimental results, to predict the concentration of each column III constituent throughout the concentration
boundary layer. Solutions to these equations are found using the two-dimensional, finite element method. The growth thickness
profiles of GaAs, InP, and InxGa1-xAs deposited by selective-area MOCVD are observed by conventional profilometry, and compositions are measured indirectly by
laser emission wavelengths. The data presented show that the model accurately predicts growth thickness and composition profiles
of ternary III-V materials grown by selective-area MOCVD. 相似文献
11.
采用金属有机化学气相沉积方法,在Si(100)衬底上生长出具有高度C轴择优取向的ZnO薄膜.通过X射线衍射、原子力显微镜和室温光致发光谱研究了厚度对ZnO薄膜的结构、表面和光学性能的影响.X射线衍射图显示ZnO薄膜只有单一的(0002)峰,具有高度择优取向.AFM和PL测试表明,在取样薄膜厚度范围内,薄膜的表面质量和发光性能没有随着薄膜厚度的增加而提高.这是因为薄膜在厚度增加的生长过程中,生长模型变化且晶粒增大. 相似文献
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Theodore Chung Jae Limb Jae-Hyun Ryou Wonseok Lee Peng Li Dongwon Yoo Xue-Bing Zhang Shyh-Chiang Shen Russell D. Dupuis David Keogh Peter Asbeck Ben Chukung Milton Feng Dimitri Zakharov Zusanne Lilienthal-Weber 《Journal of Electronic Materials》2006,35(4):695-700
The design and growth of GaN/InGaN heterojunction bipolar transistors (HBTs) by metalorganic chemical vapor deposition (MOCVD)
are studied. Atomic-force microscopy (AFM) images of p+InGaN base layers (∼100 nm) deposited under various growth conditions indicate that the optimal growth temperature is limited
to the range between 810 and 830°C due to a trade-off between surface roughness and indium incorporation. At these temperatures,
the growth pressure must be kept above 300 Torr in order to keep surface pit density under control. An InGaN graded-composition
emitter is adopted in order to reduce the number of V-shaped defects, which appear at the interface between GaN emitter and
InGaN base and render an abrupt emitter-base heterojunction nearly impossible. However, the device performance is severely
limited by the high p-type base contact resistance due to surface etching damage, which resulted from the emitter mesa etch. 相似文献
15.
研究了反应压力对金属有机化学气相沉积(MOCVD)技术制备未掺杂ZnO薄膜的微观结构和光电特性影响.X射线衍射(XRD)和扫描电子镜(SEM)的研究结果表明,随着反应压力的降低,ZnO薄膜(002)择优峰的强度呈现相对减弱趋势,并且出现了较强的(110)峰;Hall测量表明,低的反应压力有助于提高薄膜电学特性.200 Pa时制备出的ZnO薄膜具有明显的"类金字塔"状绒面结构,电阻率为1.28×10-2 Ω·cm.实验中沉积的ZnO薄膜在600~2 600 nm内平均透过率超过80%,而短波长范围由于光散射作用,ZnO薄膜的垂直透过率有所下降. 相似文献
16.
采用真空热蒸发(VTE)的方法制备了CdS多晶薄膜,研究了不同衬底温度对其微观结构与光电性能的影响。结果显示,不同衬底温度下制备的CdS薄膜均属于六方相多晶结构且具有(002)择优取向;随着衬底温度的升高,(002)特征衍射峰强度增加,半高宽变小,相应薄膜结晶度增大;由CdS薄膜的透射光谱可知,在500~1 000nm波段平均透过率均超过80%,光学带隙随着衬底温度的升高而增大(2.44~2.56eV),表明真空热蒸发方法制备的CdS薄膜可以作为CIGS薄膜太阳电池的缓冲层。将真空热蒸发法制备CdS薄膜与磁控溅射法制备CIGS薄膜太阳电池相结合,在同一真空室内得到了CIGS薄膜太阳电池器件,为CIGS薄膜太阳电池的工业化推广提供了新途径。 相似文献
17.
Effect of Se-doping on deep impurities in AlxGa1−xAs grown by metalorganic chemical vapor deposition
J. C. Chen Z. C. Huang Bing Yang H. K. Chen Tao Yu Kun-Jing Lee 《Journal of Electronic Materials》1995,24(11):1677-1682
We have studied the effect of Se-doping on deep impurities in AlxGa1−xAs (x = 0.2∼0.3) grown by metalorganic chemical vapor deposition (MOCVD). Deep impurities in various Se-doped AlxGa1−xAs layers grown on GaAs substrates were measured by deep level transient spectroscopy and secondary ion mass spectroscopy.
We have found that the commonly observed oxygen contamination-related deep levels at Ec-0.53 and 0.70 eV and germanium-related level at Ec-0.30 eV in MOCVD grown AlxGa1−xAs can be effectively eliminated by Se-doping. In addition, a deep hole level located at Ey + 0.65 eV was found for the first time in Se-doped AlxGa1-xAs when Se ≥2 × 1017 cm−3 or x ≥ 0.25. The concentration of this hole trap increases with increasing Se doping level and Al composition. Under optimized
Se-doping conditions, an extremely low deep level density (Nt less than 5 × 1012 cm−3, detection limit) Al0.22Ga0.78As layer was achieved. A p-type Al0.2Ga0.8As layer with a low deep level density was also obtained by a (Zn, Se) codoping technique. 相似文献
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Blue and green dual wavelength InGaN/GaN multi-quantum well (MQW) light-emitting diode (LED) has wide applications in full color display, monolithic white LED and solid state lighting, etc. Blue and green dual wavelength LEDs, which consist of InGaN strain-reduction layer, green InGaN/GaN MQW and blue InGaN/ GaN MQW, were grown by metal-organic chemical vapor deposition (MOCVD), and the luminescence properties of dual wavelength LEDs with different well arrangements were studied by photoluminescence and electrolumines-cence. The experimental results indicated that well position played an important role on the luminescence evolvement from photoluminescence to electroluminescence. 相似文献
20.
Y. D. Kim F. Nakamura E. Yoon D. V. Forbes X. Li J. J. Coleman 《Journal of Electronic Materials》1997,26(10):1164-1168
By monitoring the cyclic behavior of surface photoabsorption (SPA) reflectance changes during the growth of GaAs at 650°C
and with sufficient H2 purging time between the supply of trimethylgallium and AsH3, we have been able to achieve controlled growth of GaAs down to a monolayer. Our results show, as confirmed by photoluminescence
(PL) measurements, the possibility of growing highly accurate quantum well heterostructures by metalorganic chemical vapor
deposition at conventional growth temperatures. We also present our PL measurements on the InGaAs single quantum wells grown
at this temperature by monitoring the SPA signal. 相似文献