XPS Study of Electroless Deposited Sb2Se3 Thin Films for Solar Cell Absorber Material

As a thin film solar cell absorber material, antimony selenide (Sb2Se3) has become a potential candidate recently because of its unique optical and electrical properties and easy fabrication method. X-ray photoelectron spectroscopy (XPS) was used to determine the stoichiometry and composition of electroless Sb2Se3 thin films using depth profile studies. The surface layers were analyzed nearly stoichiometric. But the abundant amount of antimony makes the inner layer electrically more conductive.

Depth Profile Study of Electroless Deposited Sb2S3 Thin Films Using XPS for Photovoltaic Applications

Sb2S3 has gained tremendous research recently for thin film solar cell absorber material because of their easy synthesis, unique electrical and optical properties. The stoichiometry and composition of electroless Sb2S3 thin films were analyzed using XPS depth profile studies. The surface layers were found nearly stoichiometric. On the other hand, the inner layer was rich in antimony composition making it more conductive electrically.

Preparation and Characterization of CeO_2-TiO_2/SnO_2:Sb Films Deposited on Glass Substrates by R.F.Sputtering

CeO2-TiO2 films and CeO2-TiO/SnO2：Sb （6 mol%） double films were deposited on glass substrates by radio-frequency magnetron sputtering （R.F. Sputtering）, using SnO2：Sb（6 mol%） target, and CeO2- TiO2 targets with different molar ratio of CeO2 to TiO2 （CeO2：TiO2-0：1.0; 0.1：0.9; 0.2：0.8; 0.3：0.7; 0.4：0.6; 0.5：0.5; 0.6：0.4; 0.7：0.3; 0.8：0.2; 0.9：0.1; 1.0：0）. The films are characterized by UV-visible transmission and infrared reflection spectra, scanning electron microscopy （SEM）, Raman spectroscopy, X-ray photoelectron spectroscopy （XPS） and X-ray diffraction （XRD）, respectively. The obtained results show that the amorphous phases composed of CeO2-TiO2 play an important role in absorbing UV, there are Ce^3-, Ce^4- and Ti^4- on the surface of the films; the glass substrates coated with CeO2-TiO2 （Ce/Ti=0.5：0.5; 0.6：0.4）/SnO2：Sb（6 mol%） double films show high absorbing UV（〉99）, high visible light transmission （75%） and good infrared reflection （〉70%）. The sheet resistance of the films is 30-50 Ω/□. The glass substrates coated with the double functional films can be used as window glass of buildings, automobile and so on.

Structure distortion, optical and electrical properties of ZnO thin films co-doped with Al and Sb by sol-gel spin coating

ZnO thin films co-doped with A1 and Sb with different concentrations and a fixed molar ratio of AlCl3 to SbCl3 at 1：2, are prepared by a sol-gel spin-coating method on glass annealed at 550 ℃ for 2 h in air. The x-ray diffraction results confirm that the ZnO thin films co-doped with Al distortion, and the biaxial stresses are 1.03× 10^8. 3.26× 10^8 and Sb are of wurtzite hexagonal ZnO with a very small 5.23 × 10^8, and 6.97× 10^8 Pa, corresponding to those of the ZnO thin films co-doped with Al and Sb in concentrations of 1.5, 3.0, 4.5, 6.0 at% respectively. The optical properties reveal that the ZnO thin films co-doped with Al and Sb have obviously enhanced transmittance in the visible region. The electrical properties show that ZnO thin film co-doped with Al and Sb in a concentration of 1.5 at% has a lowest resistivity of 2.5 Ω·cm.

The electrical,optical properties of AlSb polycrystalline thin films deposited by magnetron co-sputtering without annealing

In order to fabricate A1Sb polycrystalline thin films without post annealing, this paper studies a technology of magnetron co-sputtering onto intentionally heated substrate. It compares the structural characteristics and electrical properties of A1Sb films which are deposited at different substrate temperatures. It finds that the films prepared at a substrate temperature of 450 ℃ exhibit an enhanced grain growth with an average grain size of 21 nm and the lattice constant is 0.61562 nm that goes well with unstained lattice constant （0.61355 nm）. The ln（σdark） -1/T curves show that the conductivity activation energy is about 0.38 eV when the film is deposited at 450 ℃ without an annealing. The transmittance and reflectance spectra show that the film deposited at 450 ℃ has an optical band gap of 1.6 eV. These results indicate that we have prepared A1Sb polycrystalline films which do not need a post annealing.

Multiple-State Storage Capability of Stacked Chalcogenide Films （Si16Sb33Te51/Si4Sb45Te51/Si11Sb39Te50） for Phase Change Memory

The multiple-state storage capability of phase change memory （PCM） is confirmed by using stacked chalcogenide films as the storage medium. The current-voltage characteristics and the resistance-current characteristics of the PCM clearly indicate that four states can be stored in this stacked film structure. Qualitative analysis indicates that the multiple-state storage capability of this stacked film structure is due to successive crystallizations in different Si-Sb-Te layers triggered by different amplitude currents.

Structural Evolution and Phase Change Properties of C-Doped Ge_2Sb_2Te_5 Films During Heating in Air

We elucidate the importance of a capping layer on the structural evolution and phase change properties of carbondoped Ge2 Sb2 Te5（C-GST） films during heating in air. Both the C-GST films without and with a thin SiO2 capping layer（C-GST and C-GST/SiO2） are deposited for comparison. Large differences are observed between C-GST and C-GST/SiO2 films in resistance-temperature, x-ray diffraction, x-ray photoelectron spectroscopy,Raman spectra, data retention capability and optical band gap measurements. In the C-GST film, resistancetemperature measurement reveals an unusual smooth decrease in resistance above 110℃ during heating. Xray diffraction result has excluded the possibility of phase change in the C-GST film below 170℃. The x-ray photoelectron spectroscopy experimental result reveals the evolution of Te chemical valence because of the carbon oxidation during heating. Raman spectra further demonstrate that phase changes from an amorphous state to the hexagonal state occur directly during heating in the C-GST film. The quite smooth decrease in resistance is believed to be related with the formation of Te-rich GeTe4-n Gen（n = 0, 1） units above 110℃ in the C-GST film. The oxidation of carbon is harmful to the C-GST phase change properties.

Lithium intercalation mechanism for β-SnSb in Sn-Sb thin films

Based on the first-principles plane wave pseudo-potential method, the electronic structure and electrochemical performance of LixSn4Sb4 （x=2, 4, 6, and 8） and LixSn12-xSb4 （x=9, 10, 11, and 12） phases were calculated. A Sn-Sb thin film on a Cu foil was also prepared by radio frequency magnetron sputtering. The surface morphology, composition, and lithium intercalation/extraction behavior of the fabricated film were characterized by scanning electron microscopy （SEM）, X-ray diffraction （XRD） and cyclic voltammetry （CV）. Lithium atoms can easily insert into and extract out of the β-SnSb cell due to the low lithium intercalation formation energy. It is found that lithium atoms first occupy the interstitial sites, and then Sn atoms at the lattice positions are replaced by excessive lithium. The dissociative Sn atoms continue to produce different Li-Sn phases, which will affect the electrode stability and lead to the undesirable effect due to their large volume expansion ratio. The calculated lithium intercalation potential is stable at about 0.7 V, which is consistent with the experimental result.

Quantum spin Hall insulators in chemically functionalized As(110)and Sb(110)films

We propose a new type of quantum spin Hall （QSH） insulator in chemically functionalized As （110） and Sb （110） film. According to first-principles calculations, we find that metallic As （110） and Sb （110） films become QSH insulators after being chemically functionalized by hydrogen （H） or halogen （C1 and Br） atoms. The energy gaps of the functionalized films range from 0.121 eV to 0.304 eV, which are sufficiently large for practical applications at room temperature. The energy gaps originate from the spin-orbit coupling （SOC）. The energy gap increases linearly with the increase of the SOC strength λ/λ0. The Z2 invariant and the penetration depth of the edge states are also calculated and studied for the functionalized films.

Study of Ge_2Sb_2Te_5 Film for Nonvolatile Memory Medium

The amorphous Ge2Sb2Te5 film with stoichiometric compositions was deposited by co-sputtering of separate Ge, Sb, and Te targets on SiO2/Si (100) wafer in ultrahigh vacuum magnetron sputtering apparatus. The crystallization behavior of amorphous Ge2Sb2Te5 film was investigated by X-ray diffraction (XRD), atomic force microscopy (AFM) and differential scanning calorimetry (DSC). With an increase of annealing temperature, the amorphous Ge2Sb2Te5 film undergoes a two-step crystallization process that it first crystallizes in face-centered-cubic (fcc) crystal structure and finally fcc structure changes to hexagonal (hex) structure. Activation energy values of 3.636±0.137 and 1.579±0.005 eV correspond to the crystallization and structural transformation processes, respectively. From annealing temperature dependence of the film resistivity, it is determined that the first steep decrease of the resistivity corresponds to crystallization while the second one is primarily caused by structural transformation from 'fcc' to 'hex' and growth of the crystal grains. Current-voltage (Ⅰ-Ⅴ) characteristics of the device with 40 nm-thick Ge2Sb2Te5 film show that the Ge2Sb2Te5 film with nanometer order thickness is still applicable for memory medium of nonvolatile phase change memory.

Crystallization Process of Superlattice-Like Sb/SiO_2 Thin Films for Phase Change Memory Application

After compositing with SiO_2 layers, it is shown that superlattice-like Sb/SiO_2 thin films have higher crystallization temperature（~240°C）, larger crystallization activation energy（6.22 e V）, and better data retention ability（189°C for 10 y）. The crystallization of Sb in superlattice-like Sb/SiO_2 thin films is restrained by the multilayer interfaces. The reversible resistance transition can be achieved by an electric pulse as short as 8 ns for the Sb（3 nm）/SiO_2（7 nm）-based phase change memory cell. A lower operation power consumption of 0.09 m W and a good endurance of 3.0 × 10~6 cycles are achieved. In addition, the superlattice-like Sb（3 nm）/SiO_2（7 nm） thin film shows a low thermal conductivity of 0.13 W/（m·K）.

Characteristics of Sb6Te4/VO2 Multilayer Thin Films for Good Stability and Ultrafast Speed Applied in Phase Change Memory

The Sb6 Te4/VO2 multilayer thin films are prepared by magnetron sputtering and the potential application in phase change memory is investigated in detail. Compared with Sb6 Te4, Sb6 Te4/VO2 multilayer composite thin films have higher phase change temperature and crystallization resistance, indicating better thermal stability and less power consumption. Also, Sb6 Te4/VO2 has a broader energy band of 1.58 eV and better data retention （125℃ for 103/）. The crystallization is suppressed by the multilayer interfaces in Sbf Te4/VO2 thin film with a smaller rms surface roughness for Sbf Te4/VO2 than monolayer Sb4Te6. The picosecond laser technology is applied to study the phase change speed. A short crystallization time of 5.21 ns is realized for the Sb6Te4 （2nm）/VO2 （8nm） thin film. The Sb6 Te4/VO2 multilayer thin film is a potential and competitive phase change material for its good thermal stability and fast phase change speed.

基于SnO_(2)∶Sb薄膜沉积工艺参数优化的支持向量回归分析

开发低成本高质量透明导电氧化物薄膜材料的生长技术对现代光电产业发展十分重要。面对多维的薄膜生长工艺参数空间,在寻求最优薄膜生长参数过程中如何有效降低时间、材料成本是研究人员迫切关注的问题。基于雾化辅助CVD法在石英衬底上制备SnO_(2)∶Sb薄膜,利用实验设计方法,获得不同工艺参数下制备的SnO_(2)∶Sb薄膜实验数据集。应用基于贝叶斯优化的支持向量回归方法,建立SnO_(2)∶Sb薄膜透明导电性能的支持向量回归预测模型,结合预测模型对整个工艺参数空间进行探索。利用有限27组工艺参数组合可在四维参数空间中找到高质量SnO_(2)∶Sb薄膜的有效制备参数。在最优工艺参数下制备薄膜的可见光透过率可达86.61%,方块电阻为21.1Ω·□^(-1),膜厚约380 nm。为基于雾化辅助CVD法制备薄膜材料的最优制备工艺探索提供一条有效途径,可有效节约开发成本。

Electrical and optical properties of Sb-doped ZnO thin films synthesized by sol–gel method

Sb-doped ZnO thin films with different values of Sb content （from 0 to 1.1 at.%） are deposited by the sol-gel dip- coating method under different sol concentrations. The effects of Sb-doping content, sol concentration, and annealing ambient on the structural, optical, and electrical properties of ZnO films are investigated. The results of the X-ray diffraction and ultraviolet-visible spectroscopy （UV-VIS） spectrophotometer indicate that each of all the films retains the wurtzite ZnO structure and possesses a preferred orientation along the c axis, with high transmittance （〉 90%） in the visible range. The Hall effect measurements show that the vacuum annealed thin films synthesized in the sol concentration of 0.75 mol/L each have an adjustable n-type electrical conductivity by varying Sb-doping density, and the photoluminescence （PL） spectra revealed that the defect emission （around 450 nm） is predominant. However, the thin films prepared by the sol with a concentration of 0.25 mol/L, despite their poor conductivity, have priority in ultraviolet emission, and the PL peak position shows first a blue-shift and then a red-shift with the increase of the Sb doping content.

掺锑Zn-Sn-O透明导电膜的制备及特性

采用射频磁控溅射技术在7059玻璃衬底上低温制备出具有多晶结构的掺锑锌-锡-氧(Zn-Sn-O:Sb)透明 导电膜。研究了制备薄膜的结构、成分、电学和光学特性以及退火温度对薄膜性能的影响。Zn-Sn-P:Sb透明导 电膜的电阻率为1．5×10-2Ω·cm,相应载流子浓度和霍尔迁移率分别为8．0×1019cm-3,5.8cm2·v-1·s-1。薄膜的 可见光平均透过率达到了85％。

用共蒸发法制备AlSb多晶薄膜

采用元素共蒸发法结合退火处理制成了AlSb多晶薄膜.利用X射线衍射、透射光谱、暗电导温度关系等方法研究了薄膜的结构、光学和电学性质.发现540℃退火后得到的AlSb多晶薄膜呈立方相结构,间接跃迁光能隙为1.62eV,电导激活能约为0.33eV.研究结果表明,AlSb薄膜有可能成为新型太阳电池的重要材料.

退火处理对SnO_2:Sb薄膜结构和光致发光性质的影响

用射频磁控溅射法在玻璃衬底上制备出SnO2:Sb薄膜,研究了不同掺杂和退火对薄膜结构的影响。制备薄膜是具有纯氧化锡四方金红石结构的多晶膜薄,晶粒生长的择优取向为(110)。室温下光致发光测量首次观测到392nm附近存在紫外-紫光发射,并对SnO2:Sb的光致发光机制进行了探索性研究。

CVD法制备Sb掺杂SnO_2薄膜的结构与性能研究

采用化学气相沉积法(CVD)制备了Sb掺杂SnO2薄膜(ATO),研究了Sb掺杂量对ATO薄膜结构和性能的影响.利用X射线衍射(XRD)、扫描电镜(SEM)、X射线光电子能谱(XPS)等分析手段对所制得薄膜的结构、形貌、成分等进行了表征,XRD结果表明在基板温度为665℃时能够制得结晶性能较好的多晶薄膜,XPS分析确定掺杂后的Sb以Sb5+离子形式存在.讨论了Sb掺杂量对方块电阻、透射率和反射率等薄膜性质的影响,结果表明,当Sb掺杂量为2%时取得最小方块电阻为7.8Ω/□,在可见光区薄膜的透射率和反射率随着Sb掺杂量的增加呈下降趋势.最后探讨了Sb掺杂SnO2薄膜的显色特性,认为Sb5+离子的本征吸收是薄膜显色的主要原因.

SnO_2：Sb电热膜的性能及应用

用化学纯原料制备了大功率密度的ＳｎＯ２：Ｓｂ电热度．并分析其结构研究了掺杂量、溶液浓度和退火处理对电阻及电阻温度特性的影响．用喷涂法制备的大面积、性能稳定的ＳｎＯ２：Ｓｂ电热流功率角度高达４０Ｗ．

SnO_2∶Sb/SiO_2复合薄膜的制备与光学性能

采用溶胶-凝胶结合旋涂技术在玻璃基底上制备了SnO2∶Sb/SiO2复合薄膜,利用XRD、FT-IR、SEM、椭偏仪、分光光度计等方法对薄膜样品进行了系统地表征。结果表明:经过热处理后样品生成了SnO2∶Sb和SiO2;薄膜具有双层结构,上层SiO2厚度约105 nm,折射率为1.352,底层SnO2∶Sb厚度约1200 nm,折射率为1.91;优化工艺条件下SnO2∶Sb/SiO2复合薄膜的性能优于SnO2∶Sb薄膜,在相同情况下SnO2∶Sb/SiO2复合薄膜对可见光的透过率大于SnO2∶Sb薄膜,这是因为上层SiO2薄膜折射率较低,与底层高折射率SnO2∶Sb薄膜共同构成减反射膜系,提高了膜系的可见光透过率。相比于单层SnO2∶Sb膜,在可见光部分增透率大于4.5%,近红外波段的增透率小于1.0%,基本保持原有导电膜的低红外辐射特性,并提高了可见光透过率。