非晶碲镉汞薄膜的暗电导与光电导

This paper reports the dark conductivity and photoconductivity of amorphous Hg_(0.78)Cd_(0.22)Te thin films deposited on an Al_2O_3 substrate by RF magnetron sputtering.It is determined that dark conduction activation energy is 0.417 eV for the as-grown sample.Thermal quenching is absent for the as-grown sample during the testing temperature zone,but the reverse is true for the polycrystalline sample.Photosensitivity shows the maximum at 240 K for amorphous thin films,while it is higher for the as-grown ...     

退火对非晶态碲镉汞薄膜稳定态光电导的影响

利用射频磁控溅射方法,在宝石衬底上制备了非晶态碲镉汞(a-HgCdTe)薄膜。对原生a-HgCdTe薄膜进行了不同退火时间和不同退火温度的热退火,在80～300K温度范围内,分别测量了原生和退火处理后的a-HgCdTe薄膜样品的稳定态光电导,研究了退火时间和退火温度对非晶态HgCdTe薄膜的稳定态光电导和激活能的影响。结果表明,原生和退火a-HgCdTe薄膜的稳定态光电导具有热激活特性;随着退火时间增加或退火温度升高,a-HgCdTe薄膜的晶化程度提高,导致光电导增大,光电导激活能降低。利用非晶-多晶转变机制讨论了实验结果。     

Cd组分x对非晶态Hg_(1-x)Cd_xTe薄膜暗电导的影响

利用射频溅射方法制备了非晶态Hg_(1-x)Cd_xTe薄膜(x=0,0.22,0.50,0.66,1),在80 K~300 K温度范围内,研究了Cd组分x对暗电导的影响。当温度T>210 K时,随着Cd组分增加,暗电导减小;当温度T<210 K,随着Cd组分增加,则暗电导增大;当温度T=210 K时,暗电导几乎与Cd组分无关。这可能是由于随着Cd组分增加,薄膜中的缺陷增加所致。a-Hg_(1-x)Cd_xTe(x=0、0.22、0.50、0.66和1)薄膜中存在扩展态电导和局域态电导,Cd组分x越大,两种导电机制的转变温度Tm也越高。在T=300 K时,利用暗电导的激活能估算出了非晶态Hg_(1-x)Cd_xTe薄膜的迁移率隙Eg,随着Cd组分x增加,迁移率隙Eg微弱减小。     

非晶态碲镉汞薄膜的射频磁控溅射生长及其结构和光学特性

在玻璃衬底上用射频磁控溅射技术进行了非晶态碲镉汞(α-HgCdTe,α-MCT)薄膜的低温生长.采用X射线衍射(XRD)和原子力显微(AFM)技术对所生长的薄膜进行分析研究,所生长的非晶态HgCdTe薄膜表面平整,没有晶粒出现,获得了射频磁控溅射生长非晶态HgCdTe薄膜的"生长窗口".采用傅里叶红外透射光谱分析技术对非晶态HgCdTe薄膜进行了光学性能研究,在1.0～2.0μm范围内研究了薄膜的透射谱线,获得了薄膜的吸收系数(～8×104cm-1),研究了其光学带隙(约0.83eV)和吸收边附近的3个吸收区域.     

非晶态碲镉汞薄膜的射频磁控溅射生长及其结构和光学特性

在玻璃衬底上用射频磁控溅射技术进行了非晶态碲镉汞(α-HgCdTe,α-MCT)薄膜的低温生长.采用X射线衍射(XRD)和原子力显微(AFM)技术对所生长的薄膜进行分析研究,所生长的非晶态HgCdTe薄膜表面平整,没有晶粒出现,获得了射频磁控溅射生长非晶态HgCdTe薄膜的"生长窗口".采用傅里叶红外透射光谱分析技术对非晶态HgCdTe薄膜进行了光学性能研究,在1.0～2.0μm范围内研究了薄膜的透射谱线,获得了薄膜的吸收系数(～8×104cm-1),研究了其光学带隙(约0.83eV)和吸收边附近的3个吸收区域.     

非晶态碲镉汞薄膜晶化过程的椭圆偏振光谱研究

采用椭圆偏振光谱技术研究了非晶态碲镉汞薄膜在不同退火条件下的结构性能.结果表明非晶态碲镉汞薄膜在退火过程中的成核晶化是在薄膜内部均匀发生的,对于不同晶化程度的薄膜,其光学常数谱具有明显的特征,通过对光学常数谱的分析研究可以对非晶态碲镉汞薄膜的晶化程度进行量化表征,从而控制退火条件,优化材料质量.     

碲镉汞薄膜少子寿命测试研究

碲镉汞(HgCdTe)材料的少子寿命是影响碲镉汞红外探测器性能的重要参数.分别采用微波光电导衰减(Microwave Photoconductivity Decay,μ-PCD)法和微波探测光电导(Microwave Detected Photoconductivity,MDP)法对 HgCdTe 薄膜的少子寿命进行了...     

非晶态碲镉汞薄膜的射频磁控溅射生长及其晶化过程研究

在玻璃衬底上用射频磁控溅射技术进行了非晶态碲镉汞(a-HgCdTe或a-MCT)薄膜的低温生长,获得了射频磁控溅射生长a-HgCdTe薄膜的\     

非晶态碲镉汞的光学性质

采用椭圆偏振光谱技术研究了射频磁控溅射生长非晶态碲镉汞(amorphous Hg1-xCdxTe,amorphous MCT,a-MCT)薄膜的光学性质,发现非晶态碲镉汞薄膜的介电函数谱特征与晶态碲镉汞材料的明显不同,表现出与其他非晶态半导体材料类似的“波包”结构特征.基于修正的FB模型在1.0～4.0 eV的能量范围内对实验结果进行了拟合分析,得到了不同组分非晶态碲镉汞薄膜的光学带隙随组分关系.通过与单晶碲镉汞光学带隙随组分变化关系的对比研究,结果表明碲镉汞的结构从晶态向非晶态转变过程中,材料的光学待续发生了明显的“蓝移”.     

非晶态碲镉汞的暗电导率和吸收边

研究了非晶态碲镉汞(x=0.2)薄膜的暗电导率随温度变化关系,发现非晶态结构的碲镉汞材料具有明显的半导体特性,其室温禁带宽度在0.88～0.91 eV之间,与通过光学方法获得的结果相符.在80～240K的温度区间非晶态碲镉汞(x=0.2)的暗电导率从1×10-8Ω-1·cm-1缓慢增大到5×10- 8Ω-1-cm-1,温度大于240K时,其电导率剧烈增大到1×10-5Ω-1·cm-1,说明在240K附近非晶态碲镉汞材料的导电机制发生了变化,这对非晶态碲镉汞材料的应用研究具有重要意义.还研究了退火过程对非晶态碲镉汞薄膜电导率的影响,结果表明140℃退火后非晶态碲镉汞薄膜发生了部分晶化.     

非晶InP薄膜的光学性质与退火效应

本文研究由射频溅射法制备的非晶InP薄膜的光学性质及其退火效应.薄膜光学性质由椭圆偏振光谱法测量.退火是在300、350、400、420℃的温度下于密闭容器中进行.结果表明,经400℃退火后,薄膜光学性质发生明显改变,反映薄膜已由非晶态转变为多晶态.指出用光学性质的改变来描述晶化过程可能更加灵敏.     

非晶氧化钛薄膜的电学特性研究

室温下,通过采用直流反应磁控溅射法在覆盖有氮化硅薄膜的单晶硅衬底上生长了厚度约为100nm的氧化钛薄膜。掠入射X射线衍射分析结果表明在室温下,不同氧分压下生长的氧化钛薄膜均具有非晶结构。分别采用场发射扫描电子显微镜、X射线光电子能谱对薄膜的表面和断面形貌以及薄膜的组分进行了分析和表征。对薄膜的电学特性测试发现非晶氧化钛薄膜在293～373K的温度范围内主要依靠热激发至扩展态中的电子导电。     

非晶GaN薄膜的空间电荷限制电流特性

采用直流磁控溅射技术制备了Si衬底上的非晶GaN薄膜. GaN肖特基二极管伏安曲线不能简单地用包含串联电阻和复合电流效应的热电子发射理论来解释，其他电流输运机制（空间电荷限制电流）起主要作用. 分析数据得到平衡时的电子浓度为1.1E4cm-3和位于EC-0.363eV的陷阱能级. 测量空间电荷限制电流可以用来研究宽带隙化合物非晶半导体GaN的深能级性质.     

Solid-phase Crystallization of Amorphous Silicon Films by Rapid Thermal Annealing

The morphous silicon films prepared by PECVD at substrate temperatures of 30℃ have been crystallized by rapid thermal annealing method, the budget of time-temperature in the annealing process is 600℃ for 120s, 850℃ for 120s, and 950℃ for 120s. The results indicate the crystallization at 850℃ and 950℃ are better as shown in micro-Raman scattering and scanning electronic microscope.     

Out-of-Plane Magnetic Anisotropy and Microwave Permeability of Magnetoelastic FeCoSiB Amorphous Thin Films

Theamorphous magnetoelastic Fe66Co17Si1B6 thin films have been deposited by dc magnetron sputtering. A lot of ＂nano-trenches＂ have been observed on the fdm surfaces by AFM. The permeability of amorphous Fe66COlTSilB6 thin films was measured within the frequency range of 0.6GHz-10.2 GHz. The ferromagnetic resonance frequency was found to be 1.2 GHz. MFM shows that the domain of thin film is a maze-type pattern, which indicates that an out-of-plane magnetic anisotropy exists. The out-of-plane anisotropy is believed due to the stress-induced magnetic anisotropy. It can be inferred that the internal stress is tensile stress and normal to the film plane. Index Terms     

非晶硅薄膜光谱响应研究

利用Matlab软件计算了基于本征吸收的非晶硅薄膜的光谱响应,仿真出由多个不同带隙的薄膜组成的非晶硅薄膜的光谱响应,仿真了薄膜厚度、光学禁带宽度参数对非晶硅薄膜光谱响应的影响,设计出一种渐变带隙的非晶硅薄膜。结果表明渐变带隙的非晶硅薄膜能有效拓宽薄膜的光谱响应范围,也能提高光谱中对各个波长的响应值。     

快速光热退火法制备多晶硅薄膜的研究

为了制备应用于太阳电池的优质多晶硅薄膜,研究了非晶硅薄膜的快速光热退火技术。先利用 PECVD 设备沉积非晶硅薄膜,然后放入快速光热退火炉中进行退火。退火前后的薄膜利用 X 射线衍射仪(XRD)和扫描电子显微镜(SEM)测试其晶体结构及表面形貌,用电导率设备测试其暗电导率。研究表明退火温度、退火时间对非晶硅薄膜的晶化都有很大的影响,光热退火前先用常规高温炉预热有助于增大多晶硅薄膜的晶粒尺寸和暗电导率。     

Passivation Properties and Formation Mechanism of Amorphous Halide Perovskite Thin Films

Lead halide perovskites are among the most exciting classes of optoelectronic materials due to their unique ability to form high-quality crystals with tunable bandgaps in the visible and near-infrared using simple solution precipitation reactions. This facile crystallization is driven by their ionic nature; just as with other salts, it is challenging to form amorphous halide perovskites, particularly in thin-film form where they can most easily be studied. Here, rapid desolvation promoted by the addition of acetate precursors is shown as a general method for making amorphous lead halide perovskite films with a wide variety of compositions, including those using common organic cations (methylammonium and formamidinium) and anions (bromide and iodide). By controlling the amount of acetate, it is possible to tune from fully crystalline to fully amorphous films, with an interesting intermediate state consisting of crystalline islands embedded in an amorphous matrix. The amorphous lead halide perovskite has a large and tunable optical bandgap. It improves the photoluminescence quantum yield and lifetime of incorporated crystalline perovskite, opening up the intriguing possibility of using amorphous perovskite as a passivating contact, as is currently done in record efficiency silicon solar cells.     

Barrier Properties of Amorphous Binary Ta-Ni Thin Films for Cu Interconnection

Highly thermally stable amorphous Ta _x Ni_1–x (x = 0.25 and 0.75) thin films were deposited on Si and Si/SiO₂ substrate by magnetron dc sputtering, and the performance of films (20-nm thick) as barriers for copper (Cu) interconnection was evaluated. The failure behaviors of the films were elucidated using a four-point probe, x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Auger emission spectrometry (AES). A highly (111) textured Cu film could be obtained when Cu was deposited on Si/Ta_0.25Ni_0.75 and Si/SiO₂/Ta_0.25Ni_0.75 substrates. The failure temperatures of Si/Ta_0.25Ni_0.75/Cu- and Si/Ta_0.75Ni_0.25/Cu-stacked films were 550°C and 600°C, respectively. Failure of the studied films initiated the penetration of Cu into the Si/Ta _x Ni_1–x interface and triggered the partial dissociation of the Ta _x Ni_1–x barrier layer, forming Cu₃Si precipitates, Ni-silicide and Ta-silicide. Increasing the Ta content enhanced the microstructural and thermal stability of the stacked films, markedly improving barrier properties. The experimental findings demonstrated that the barrier characteristic of Ta_0.75Ni_0.25 was substantially superior to that of Ta_0.25Ni_0.75.     

非晶态锑化铟薄膜的射频磁控溅射生长及其结构和光学特性研究

在玻璃衬底上用射频磁控溅射技术进行了非晶态锑化铟(a-InSb)薄膜的低温生长.采用X射线衍射(XRD)和原子力显微(AFM)技术对所生长的薄膜进行分析研究,所生长的非晶态锑化铟薄膜表面平整,没有晶粒出现,获得了射频磁控溅射生长非晶态锑化铟薄膜的\