Physical properties of sprayed antimony doped tin oxide thin films:The role of thickness

Transparent conducting antimony doped tin oxide（Sb:SnO₂） thin films have been deposited onto preheated glass substrates using a spray pyrolysis technique by varying the quantity of spraying solution.The structural, morphological,X-ray photoelectron spectroscopy,optical,photoluminescence and electrical properties of these films have been studied.It is found that the films are polycrystalline in nature with a tetragonal crystal structure having orientation along the（211） and（112） planes.Polyhedrons like grains appear in the FE-SEM images. The average grain size increases with increasing spraying quantity.The compositional analysis and electronic behaviour of Sb:SnO₂ thin films were studied using X-ray photoelectron spectroscopy.The binding energy of Sn3d_5/2 for all samples shows the Sn⁴⁺ bonding state from SnO₂.An intensive violet luminescence peak near 395 nm is observed at room temperature due to oxygen vacancies or donor levels formed by Sb⁵⁺ ions.The film deposited with 20 cc solution shows 70%transmittance at 550 nm leading to the highest figure of merit(2.11×10^-3Ω^-1). The resistivity and carrier concentration vary over 1.22×10^-3 to 0.89×10^-3Ω·cm and 5.19×10²⁰ to 8.52×10²⁰ cm^-3,respectively.     

美瞳——TCL Q510

Q510少了一份Q520所具有的女人味,多了一份调皮和可爱。虽未继续采用Q520的镜面设计,但Q510却有自己独特的“大眼睛”,在屏幕周围加上了一圈弧形设计,看上云的确像足了一只眼睛。和Q520相比,Q510体积更小,体重要轻,功能却并未     

实用运算放大器网络中的虚地性质

本文提出用一个理想电压控制电流源(VCCS)并接于嵌在一个倒相放大器电路中的实际运算放大器(OP.amp)输入端,虚地性质(VGP)可以扩展到使用的运算放大器单位增益带宽那样高的频率.文中给出用真正运算放大器的VCCS的实用电路.用互补变换法可得出非倒相放大电路图.     

Analysis of charge density and Fermi level of AlInSb/InSb single-gate high electron mobility transistor

A compact model is proposed to derive the charge density of the AlInSb/InSb HEMT devices by considering the variation of Fermi level, the first subband, the second subband and sheet carrier charge density with applied gate voltage. The proposed model considers the Fermi level dependence of charge density and vice versa. The analytical results generated by the proposed model are compared and they agree well with the experimental results. The developed model can be used to implement a physics based compact model for an InSb HEMT device in SPICE applications.     

Y_2O_3-Al_2O_3系统相稳定性研究

研究了Y_2O_3Al_2O_3准二元系内三种已知相的稳定性。YAlO_3(YAP)和Y_4Al_2O_9(YAM)升温下分解,反应物是第三种化合物Y_3Al_5O_(12)(YAG)和未知相(称之为X)。这种分解在粉末中最明显,但是也开始在块状单晶表面上分解。为了验证这种未知相的结构和组分,曾进行了X-射线衍射研究。发现这种热分解是可控制的表面,对YAlO_3的有关形态变化进行光学和扫描电子显微镜研究表明,这种反应包括局部表面熔化,多半是缺氧,它有效地使组份偏离二元组合。     

红外二极管激光器双光束分光计

本文介绍纪录高分辨率红外吸收光谱的一台带二极激光器的完整的分光计。其光学装置不仅适合二极管激光器的特点,而且也可以与其它激光光源连用。由于采用双光束技术,解决了激光功率变化的问题。本文还讨论光学调校和电子信号检测问题,并且介绍其典型光谱。     

砷化镓表面的表征

本文讨论用机械的和化学的方法制备砷化镓晶体表面。利用不同的化学腐蚀剂对逐次抛光过程中的各表面进行对比研究。用显微法定性地和用 Rutherford 反向散射/沟道法定量地鉴定表面。计算了抛光表面上的镓和砷的浓度,发现表面通常是富砷的,其富砷量与所用的化学抛光液有关。测量了低的表面杂质浓度(如碲≥2×10~(13)原子/厘米~2),在两次化学抛光之间测定浓度的变化。发现杂质浓度的变化是不规律的。     

利用振荡滤波器的辐射源搜索系统

对于热辐射目标的红外系统的探测和跟踪性能主要受到两种噪声源的限制:即1)内部噪声如探测器或颤噪声;2)外部噪声或背景不均匀辐射分布引起的杂乱回波噪声。这两种噪声都使目前的系统达不到受背景噪声限制的最终灵敏度极限。但在绝大多数实际情况中,后一种噪声尤为严重,但也有例外,即在暗道中测量时能达到系统噪声限制的灵敏度而在自然背景中只能接近。由于这种原因,设计红外探测系统对于杂乱回     

Effect of deposition conditions on the physical properties of SnxSy thin films prepared by the spray pyrolysis technique

Tin sulfide thin films (Sn_xS_y) with an atomic ratio of y/x = 0.5 have been deposited on a glass substrate by spray pyrolysis. The effects of deposition parameters, such as spray solution rate (R), substrate temperature (T_s) and film thickness (t), on the structural, optical, thermo-electrical and photoconductivity related properties of the films have been studied. The precursor solution was prepared by dissolving tin chloride (SnCl₄, 5H₂O) and thiourea in propanol, and Sn_xS_y thin film was prepared with a mole ratio of y/x = 0.5. The prepared films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-vis spectroscopy. It is indicated that the XRD patterns of Sn_xS_x films have amorphous and polycrystalline structures and the size of the grains has been changed from 7 to 16 nm. The optical gap of Sn_xS_x thin films is determined to be about 2.41 to 3.08 eV by a plot of the variation of (αhν)² versus hν related to the change of deposition conditions. The thermoelectric and photo-conductivity measurement results for the films show that these properties are depend considerably on the deposition parameters.