共查询到19条相似文献,搜索用时 421 毫秒
1.
利用磁控溅射方法改变氧气含量制备了一系列NiO∶Cu/ZnO异质pn结。实验结果表明,氧含量对NiO∶Cu/ZnO异质pn结电学影响很大。相对于纯氩溅射,引入一定氧气(O2/(Ar+O2)比例为30%)后,NiO∶Cu/ZnO异质pn结的整流特性明显得到改善。与此同时,NiO∶Cu/ZnO异质pn结的光透过率也从40%增大到80%。这可能是由于氧气的轻量引入致使NiO∶Cu/ZnO异质pn结的结晶得到改善,薄膜内缺陷减少所致。进一步提高氧气含量,直到O2/(Ar+O2)比例至80%后,异质结的整流特性有所削弱,这可能是由于过多氧气的引入造成薄膜缺陷再次增多,进而影响到异质结的整流特性。这一结论得到了EDS、XRD、AFM和UV结果的支持。 相似文献
2.
利用固相反应法制备Pr0.5Ca0.5MnO3(PCMO)靶材,并采用脉冲激光沉积法(PLD)在n型Si(111)基片上沉积PCMO外延薄膜,研究了薄膜的输运特性及薄膜与Si衬底形成异质结的整流特性.结果表明:在80—300 K温度范围内,PCMO薄膜的阻温关系符合变程跳跃模型,随着温度的升高表现出从一维到二维再到三维的转变,分析认为可能源于轨道自由度对电子输运特性的影响.PCMO/Si异质结在磁场作用下整流特性得到改善,且在正向电流方向出
关键词:
0.5Ca0.5MnO3')" href="#">Pr0.5Ca0.5MnO3
Si
整流
正磁电阻 相似文献
3.
利用直流反应溅射方法在p型Si衬底上生长掺Al的n型ZnO薄膜,测量了由n型ZnO薄膜和p型Si衬底组成的异质结在黑暗和光照条件下的I-V特性,结果表明该异质结具有优良的整流特性,而且在光照条件下的反向电流迅速增大并很快趋于饱和.通过测量ZnO薄膜的光电流和异质结的光电压的光谱响应,初步分析了异质结的光电转换机理.测量结果显示,在入射光波长为380nm时光电流强度明显下降,反映出光电流与ZnO薄膜禁带宽度的密切关系;同时还发现,在与ZnO禁带宽度相对应的波长前后所产生的光生电压方向相反.推测这一现象与异质结的能带结构密切相关.
关键词:
ZnO薄膜
异质结
光电转换
光谱响应 相似文献
4.
采用磁控溅射法制备的La1-xSrxMnO3 (LSMO)/TiO2异质pn结表现出很好的整流特性.室温电流电压特性曲线显示随着Sr掺杂的增加,扩散电压增大,这可能由于Sr掺杂的增加导致载流子浓度增大所致.电流电压变温特性曲线显示随着测量温度的降低,扩散电压增大,这可能由于随着测量温度的变化导致界面电子结构的变化所致.值得提出的,异质pn结电阻随温度变化曲线表现出单层LSMO的金属绝缘相变特性,并且在低测量温度时表现出随着测量温度的降低结电阻增大,这可能是由于宽带隙的TiO2的引入导致.
关键词:
异质结
整流特性
庞磁阻 相似文献
5.
通过脉冲激光沉积(PLD)方法在Si(100)衬底上沉积一层高质量的ZnO籽晶层,在籽晶层上进一步采用超声喷雾热分解(USP)法生长ZnO薄膜,研究了籽晶层对ZnO薄膜结晶质量和ZnO/Si异质结光电特性的影响。研究结果表明,在籽晶层的诱导作用下,USP法生长ZnO薄膜由多取向结构变为(002)单一取向,结晶性能得到了显著改善;籽晶层上生长的薄膜呈现出垂直于衬底生长的柱状晶结构,微观结构更加致密。通过研究紫外光照前后ZnO/Si异质结的整流特性,发现引入籽晶层后,反向偏压下异质结的光电响应显著增加,并且在开路状态下出现明显的光伏效应。 相似文献
6.
采用脉冲激光沉积法制备了La0.88Te0.12MnO3(LTMO)/Si异质结,该异质结具有光生伏特效应和良好的整流特性.光生电压在394 μs的时间内很快增加到最大值然后逐渐减小.在T=80 K时,光生电压的最大值大约是13.7 mV.随着温度的升高,热涨落致使光生电压最大值总体呈现减小趋势,而且是非线性减小,这主要是由LTMO层发生金属绝缘体转变而导致的LTMO层能带结构的变化引起的.
关键词:
异质结
光生伏特效应
电子掺杂 相似文献
7.
利用脉冲激光沉积法成功制备了BaTiO3/p-Si异质结, 该异质结在80–300 K 显示出了良好的整流特性和光诱导特性. 开启电压随着温度的升高而逐渐降低. 利用不同频率的光子辐照样品, 观察到明显的光电导效应. 且随着照射光子能量的增大, 结电流也相应变大, 光诱导效应越明显. BaTiO3薄膜电阻-温度(R-T) 曲线显示氧缺陷条件下BaTiO3薄膜具有良好的半导体特性.
关键词:
异质结
光诱导效应
3薄膜')" href="#">BaTiO3薄膜 相似文献
8.
应用磁控溅射法以Ni-Al同时作为Cu与SiO2/Si,Cu与SRO薄膜之间的阻挡层材料,将Cu与SiO2/Si衬底和氧化物薄膜电极隔离,避免它们在高温氧气氛中发生化学反应和互扩散,实现了Cu薄膜与氧化物铁电电容器的集成.采用X射线衍射仪(XRD)和原子力显微镜(AFM)研究了不同温度下快速退火的SrRuO3(SRO)/Ni-Al/Cu/Ni-Al/SiO2/Si含Cu异质结的微结构和表面形貌,结果发现SRO/Ni-Al/Cu/Ni-Al/SiO2/Si含Cu多层异质结薄膜在高达750 ℃仍然具有较强的Cu衍射峰和比较平整的表面,显示出了很好的高温热稳定性.研究了"室温长高温退"和"低温长高温退"两种工艺手段,发现在制备含Cu多层氧化物薄膜异质结时,低温长高温后退火的方式要优于常规的室温长高温后退火方式,通过低温长高温退工艺可以缓解应力、削弱界面粗化和避免高温生长对阻挡层和Cu薄膜结构的破坏.最后结合sol-gel法将Pb(Zr0.4Ti0.6)O3(PZT)生长在该含Cu异质结上,制备得SRO/PZT/SRO/Ni-Al/Cu/Ni-Al/SiO2/Si含Cu铁电电容器,研究了电容器的薄膜结构、铁电性能和漏电特性等,发现制备的含Cu铁电电容器具有很好的铁电性能,如电滞回线趋势饱和,剩余极化强度高达~42 μC/cm2,矫顽电压为~1.0 V,介电常数~1600,漏电流~1.83×10-4 A/cm2,以及良好的抗疲劳特性和保持特性等,表明导电性优良的Cu薄膜可以应用于高密度高性能铁电电容器.对其漏电机理研究表明,SRO/PZT/SRO含Cu铁电电容器满足空间电荷限制传导机理.
关键词:
Cu
PZT
铁电电容器
Ni-Al 相似文献
9.
10.
11.
利用应变SiGe/Si异质pn结电容-电压(C-V)特性确定SiGe禁带宽度的技术.该技术根据SiGe/Si异质pn结C-V实验曲线,计算出 pn结接触电势差,并得到SiGe/Si的价带偏移量和导带偏移量,进而求得SiGe禁带宽度.该技术测试方法简便,其过程物理意义清晰,既适用于分立的SiGe/Si异质pn结,也可直接分析SiGe/Si异质结器件中的SiGe 禁带宽度.实验结果与理论计算及其他相关文献报道的结果符合较好.
关键词:
SiGe/Si
异质pn结
C-V
禁带宽度 相似文献
12.
The photovoltaic properties of heterojunctions of titanium dioxide (TiO2) nanoparticle films with single crystal silicon (c-Si) substrates with different Fermi level (E f) positions were studied. The TiO2 nanoparticles of rutile and anatase structures were studied without any sintering process. To clarify the photovoltaic properties, the characteristics of the heterojunction solar cells of TiO2 nanoparticle films with p-Si and n-Si substrates were investigated, where several Si substrates with different resistivities were used. The I–V characteristics of p-Si/TiO2 heterojunction showed the rectifying behavior and photovoltaic effect. The n-Si/TiO2 heterojunction also showed good rectifying characteristics; however, the conversion efficiency was extremely lower than that of p-Si/TiO2 heterojunction. The conversion efficiencies of various Si/TiO2 (rutile) heterojunction solar cells against the Fermi level E f of c-Si showed the maximum in the p-doped region. The photovoltaic properties of the Si/TiO2 heterojunction also depended on the crystal structure of TiO2, and the conversion efficiency of anatase is higher than that of rutile, which was attributed to the higher carrier mobility of anatase. 相似文献
13.
The Cu–CdSe–Cu nanowire heterojunctions were fabricated by sequential electrochemical deposition of layers of Cu metal and
CdSe semiconductor within the nano-pores of anodic alumina membrane templates. X-ray diffraction reveals the cubic phase for
Cu and hexagonal phase for CdSe in the electrodeposited Cu–CdSe–Cu nanowire heterojunctions. The composition of the nanowire
heterojunction segments is characterized by energy dispersive X-ray spectroscopy. The morphological study of nanowire heterojunctions
has been made using scanning electron microscope and high resolution transmission microscopy. The nanowire heterojunctions
grown in 100 and 300 nm nano-pore size templates have been found to have optical band gaps of 1.92 and 1.75 eV, respectively.
The absorption spectra of 100 nm nanowire heterojunctions show a blue shift of 0.18 eV. The collective nonlinear current–voltage
(I–V) characteristics of the 300 and 100 nm nanowire heterojunctions show their rectifying and asymmetric behaviour, respectively. 相似文献
14.
Tao Chen Shu-Yi Liu Qi Xie Christophe Detavernier R. L. Van Meirhaeghe Xin-Ping Qu 《Applied Physics A: Materials Science & Processing》2010,98(2):357-365
The effects of deposition conditions on the physical and electrical performance of the n-ZnO/p-Si heterojunction were systematically investigated. ZnO films were deposited on the Si and glass substrates using direct current (DC) magnetron sputtering with various ambients and substrate temperatures. The results showed that increasing the O2 content and substrate temperature during the deposition process could improve the crystallinity and stoichiometry of the ZnO film, resulting in a lower carrier concentration and higher resistivity. The electrical properties of the n-ZnO/p-Si heterojunctions were also affected by the deposition parameters. For the junctions fabricated in the pure Ar ambient, the sample deposited at room temperature (RT) showed Ohmic behavior, while the one deposited at 300?°C exhibited poor rectifying behavior. On the other hand, the junctions fabricated in the O2/Ar ambient possessed ideal rectifying behaviors. The different carrier transport mechanisms for the heterojunctions under forward and reverse bias were systematically studied using a high temperature current–voltage (I-V) measurement. The recombination-tunneling current showed temperature insensitive performance while the space-charge limited current (SCLC) changed with the measurement temperature. 相似文献
15.
In this study, structural and optoelectronic properties and photodedection characteristics of diodes constructed from p-zinc telluride (ZnTe) thin film/n-silicon (Si) nanowire heterojunctions are reported. Dense arrays of vertically aligned Si nanowires were successfully synthesized on (1 1 0)-oriented n-type single crystalline Si wafer using simple and inexpensive metal-assisted etching (MAE) process. Following the nanowire synthesis, p-type ZnTe thin films were deposited onto vertically oriented Si nanowires via radio frequency magnetron sputtering to form three-dimensional heterojunctions. A comparative study of the structural results obtained from X-ray diffraction and Raman spectroscopy measurements showed the improved crystallinity of the ZnTe thin films deposited onto the Si nanowire arrays. The fabricated nanowire-based heterojunction devices exhibited remarkable diode characteristics and enhanced optoelectronic properties and photosensitivity in comparison to the planar reference. The electrical measurements revealed that the diodes with nanowires had a well-defined rectifying behaviour with a rectification ratio of 104 at ±2 V and a relatively small ideality factor of n = 1.8 with lower reverse leakage current and series resistance at room temperature in dark condition. Moreover, an open-circuit voltage of 100 mV was also observed under illumination. Based on spectral photoresponsivity measurements, the nanowire-based device exhibited a distinct responsivity and high detectivity in visible and near-infrared (NIR) wavelength regions. The device characteristics observed here offer that the fabricated ZnTe thin film/Si nanowire-based p–n heterojunction structures will find important applications in future and will be a promising candidate for high-performance and low-cost optoelectronic device applications, NIR photodedectors in particular. 相似文献
16.
The Si on SiC heterojunction is still poorly understood,
although it has a number of potential applications in electronic and
optoelectronic devices, for example, light-activated SiC power
switches where Si may play the role of an light absorbing layer. This
paper reports on Si films heteroepitaxially grown on the Si face of
(0001) n-type 6H-SiC substrates and the use of B2H_6 as a
dopant for p-Si grown at temperatures in a range of
700--950~\du. X-ray diffraction (XRD) analysis and transmission
electron microscopy (TEM) tests have demonstrated that the samples
prepared at the temperatures ranged from 850~℃ to 900~℃ are
characterized as monocrystalline silicon. The rocking XRD curves
show a well symmetry with FWHM of 0.4339° Omega. Twin
crystals and stacking faults observed in the epitaxial layers might
be responsible for widening of the rocking curves. Dependence of the
crystal structure and surface topography on growth temperature is
discussed based on the experimental results. The energy band structure
and rectifying characteristics of the Si/SiC heterojunctions are
also preliminarily tested. 相似文献
17.
18.
采用磁控溅射法制备的La1-xSrxMnO3(LSMO)/TiO2异质pn结表现出很好的整流特性.室温电流电压特性曲线显示随着Sr掺杂的增加,扩散电压增大,这可能由于Sr掺杂的增加导致载流子浓度增大所致.电流电压变温特性曲线显示随着测量温度的降低,扩散电压增大,这可能由于随着测量温度的变化导致界面电子结构的变化所致.值得提出的,异质pn结电阻随温度变化曲线表现出单层LSMO的金属绝缘相变特性,并且在低测量温度时表现出随着测量温度的降低结电阻增大,这可能是由于宽带隙的TiO2的引入导致. 相似文献
19.
Rectifying effect of heterojunctions between metals and doped conducting polymer nanostructure pellets 下载免费PDF全文
This paper reports that the Schottky junctions between low work function metals (e.g. Al and In) and doped semiconducting polymer pellets (e.g. polyaniline (PANI) microsphere pellet and polypyrrole (PPy) nanotube pellet) have been prepared and studied. Since Ag is a high work function metal which can make an ohmic contact with polymer, silver paste was used to fabricate the electrodes. The Al/PANI/Ag heterojunction shows an obvious rectifying effect as shown in I - V characteristic curves (rectifying ratio γ = 5 at ±6 V bias at room temperature). As compared to the Al/PANI/Ag, the heterojunction between In and PANI (In/PANI/Ag) exhibits a lower rectifying ratio γ= 1.6 at ±2 V bias at room temperature. In addition, rectifying effect was also observed in the heterojunctions Al/PPy/Ag (γ = 3.2 at ±1.6 V bias) and In/PPy/Ag (γ = 1.2 at ±3.0 V bias). The results were discussed in terms of thermoionic emission theory. 相似文献