掺杂浓度对AZO薄膜结构和光电性能的影响

采用溶胶-凝胶(Sol-Gel)工艺在普通玻璃基片上成功地制备出高c轴择优取向性、高可见光透过率和低电阻率的Al3+掺杂型的ZnO透明导电薄膜,对这种薄膜进行了X-射线衍射和扫描电镜分析,并对其光电性能作了详细的研究。结果表明,制备的薄膜为钎锌矿型结构,呈c轴方向择优生长;其可见光透过率可达85%以上;Al3+掺杂型的ZnO透明导电薄膜的电阻率在1.5×10-2~8.2×10-2Ω.cm。     

Ga Al In掺杂ZnO电子结构的第一性原理计算

计算了Ga、Al、In掺杂ZnO体系电子结构,分析了掺杂对ZnO晶体的结构、能带、电子态密度、差分电荷分布的影响。所有计算,都是基于密度泛函理论(DFT)框架下的第一性原理平面波超软赝势方法。计算结果表明:在导带底引入了大量由掺杂原子贡献的导电载流子(Ga:2.57×1021cm–3;Al:2.58×1021cm–3;In:2.53×1021cm–3),明显提高了体系的电导率。同时,光学带隙展宽,且向低能方向漂移,可作为优良的透明导电薄膜材料。     

溅射功率对Zr,Al共掺杂ZnO薄膜结构和性能的影响

室温下,采用直流磁控溅射法,在载玻片衬底上制备出了Zr,Al共掺杂ZnO(AZZO)透明导电薄膜。研究了溅射功率对薄膜的组织结构、表面形貌和光电学性能的影响。结果表明,制备的AZZO透明导电薄膜为六角纤锌矿结构的多晶薄膜,且具有c轴择优取向。当溅射功率为150W时,薄膜电阻率达到最小值1.66×10–3Ω·cm,在可见光区平均透过率超过93%。     

中频脉冲磁控溅射制备ZnO:Al透明导电薄膜

采用中频磁控溅射工艺,以2%的Al掺杂的Zn(纯度99.99%)金属材料为靶材制备平面及绒面透明导电ZnO:Al(ZAO)薄膜,系统研究了衬底温度、工作气压和溅射功率等对平面ZAO结构和光电特性的影响,并对湿法腐蚀制备绒面ZAO薄膜进行了介绍。获得了适合太阳电池的高性能薄膜,其电阻率为4.6×10-4Ω·cm,载流子浓度为4.9×1020cm-3,霍尔迁移率为56cm2/V·s,可见光范围内(400~800nm)的平均透过率大于85%。     

衬底温度和溅射偏压对ZnO:Al透明导电膜结构和光电特性的影响

利用射频磁控溅射法在有机薄膜衬底和7059玻璃衬底上制备出了具有良好附着性的低电阻率的 ZnO:Al透明导电膜。研究了薄膜的结构和光电特性与衬底温度的关系,薄膜为多晶纤锌矿结构,垂直于衬底的 c 轴具有[002]方向的择优取向,薄膜的最低电阻率分别为 1.01×10–3ù·cm 和 8.48×10–4ù·cm,在可见光区的平均透过率分别达到了72%和 85%。并研究了溅射偏压对有机衬底 ZnO:Al 薄膜结构及光电特性影响,最佳负偏压为 60 V。     

(Al,Zr)共掺杂ZnO透明导电薄膜的结构以及光电性能研究

用射频磁控溅射法在玻璃衬底上氩气气氛中制备出(Al,Zr)共掺杂的ZnO透明导电薄膜,研究了不同Zr掺杂浓度和薄膜厚度ZnO薄膜的结构、电学和光学特性。结果表明,在最佳沉积条件下我们制备出了具有(002)单一择优取向的多晶六角纤锌矿结构,电阻率为2.2×10-2Ω.cm,且可见光段(320～800nm)平均透过率达到85%的ZnO透明导电薄膜。在150℃的条件下对(Al,Zr)共掺杂的ZnO薄膜进行1h的退火处理,薄膜电阻率降低至8.4×10-3Ω.cm。Zr杂质的掺入改善了薄膜的可见光透光性。     

In掺杂ZnO透明导电薄膜光电性质的研究

采用射频磁控溅射技术成功制备出无掺杂和In掺杂的ZnO透明导电薄膜.研究了In掺杂对薄膜的结构和光电性能的影响.结果表明,In掺杂有利于提高ZnO薄膜结晶度,使薄膜表面更加致密平整;由于In3+替代了Zn2+,提供了大量的剩余电子,使薄膜的导电性质得到了很大的提高,所得薄膜的最小电阻率为4.3×10-3Q·cm.制备的ZnO薄膜在可见光范围的透过率达到了85%,In的掺杂对透光率的影响不大.     

AZO透明导电薄膜的结构与光电性能

采用射频溅射工艺制备了Zn1-xAlxO透明导电薄膜。通过XRD、UV透射和电学性能测试等分析手段,研究了Al浓度对薄膜的组织结构和光电性能的影响规律。结果表明:薄膜具有c轴择优取向,随着Al浓度的增加,(002)衍射峰向高角度移动,峰强度逐渐减弱,x(Al)为15%掺杂极限浓度。x(Al)为2%时,薄膜电阻率是3.4×10–4Ω.cm。随着掺杂量x(Al)从0增加到20%,薄膜的禁带宽度从3.34 eV增加到4.0 eV。     

腐蚀法制备绒面ZnO透明导电薄膜

利用中频脉冲磁控溅射系统制备高透过率、高电导率的平面ZnO薄膜。对平面ZnO薄膜进行短时间弱酸腐蚀,可以获得绒面效果的ZnO透明导电薄膜。分析了工作气压和衬底温度对薄膜绒面结构的影响,获得了适合薄膜太阳能电池的绒面ZnO透明导电薄膜。当压力控制在1.92Pa左右,衬底温度150～170℃范围内沉积的薄膜具有最佳的绒面和较低的电阻率,电阻率可达5.57×10-4Ω·cm,载流子浓度2.2×1020cm-3,霍尔迁移率40.1cm2/V·s,在可见光范围平均透过率超过85%。     

sol-gel法制备的ZnO:(Al,La)透明导电膜光电性能

通过X射线衍射、紫外–可见分光光度计、扫描电镜和四探针仪分析等手段,考察了退火温度对ZnO:(Al,La)薄膜微观结构、光学和电学性能的影响,Al掺杂浓度对电阻率的影响。结果表明:随退火温度的升高,薄膜(002)晶面择优取向生长增强,平均晶粒尺寸增大,电阻率降低,透光率上升。在x(Al)为1%,退火温度550℃时,薄膜最低电阻率为1.78×10–3?·cm,平均透光率超过85%。     

The effect of introducing Al ions in cationic deposition bath on as-prepared PbS thin film through SILAR deposition method

Undoped and Al doped lead sulfide (PbS) thin films were grown on soda lime glass substrates by Successive Ionic Layer Adsorption and Reaction (SILAR) deposition method. Al content in aqueous cationic solution was varied by adding 0.5–2% of aluminum nitrate in step of 0.5. The characterization of the film was carried out using X-ray diffraction, scanning electron microscopy, and optical and electrical measurement techniques. X-ray diffraction analysis revealed that both the undoped and doped films were polycrystalline and exhibited galena type cubic structure with average crystallite size in the range of 15.5–30.9 nm. The compositional analysis results indicated that Pb, S and Al were present in the samples. Optical studies revealed prominent blue-shift in the absorption edge of as-deposited samples upon doping as compared to that of bulk PbS and this shift was due to a quantum confinement effect. The room temperature conductivity of the PbS thin films was in the range of 1.343×10⁻⁷–1.009×10⁻⁶ (Ω cm)⁻¹for doped samples and 5.172×10⁻⁸ for undoped PbS thin film sample. The optical band gap energy has inverse relation with grain size and electrical conductivity is closely related to structural parameters like grain size, crystallinity and microstrain. The estimated lattice parameter, grain size, optical band gaps and electrical properties were correlated with Al concentration in the cationic solution.     

Properties of fluorine-doped SnO2 thin films by a green sol–gel method

Fluorine doped tin oxide (FTO) films were fabricated on a glass substrate by a green sol–gel dip-coating process. Non-toxic SnF₂ was used as fluorine source to replace toxic HF or NH₄F. Effect of SnF₂ content, 0–10 mol%, on structure, electrical resistivity, and optical transmittance of the films were investigated using X-ray diffraction, Hall effect measurements, and UV–vis spectra. Structural analysis revealed that the films are polycrystalline with a tetragonal crystal structure. Grain size varies from 43 to 21 nm with increasing fluorine concentration, which in fact critically impacts resultant electrical and optical properties. The 500 °C-annealed FTO film containing 6 mol% SnF₂ shows the lowest electrical resistivity 7.0×10⁻⁴ Ω cm, carrier concentration 1.1×10²¹ cm⁻³, Hall mobility 8.1 cm²V⁻¹ s⁻¹, optical transmittance 90.1% and optical band-gap 3.91 eV. The 6 mol% SnF₂ added film has the highest figure of merit 2.43×10⁻² Ω⁻¹ which is four times higher than that of un-doped FTO films. Because of the promising electrical and optical properties, F-doped thin films prepared by this green process are well-suited for use in all aspects of transparent conducting oxide.     

The effect of bombardment with carbon ions on the nanostructure of diamond-like films

The effect of irradiation with carbon ions on the nanocluster structure of diamond-like carbon films was studied. It is shown that the electronic properties (optical absorption and electrical conductivity at low temperatures) of the films depend heavily on the ion dose, which is a consequence of the quantum confinement effect. Variations in the optical band gap and in the activation energy for hopping conductivity are indicative of an increase in the size of π clusters whose concentration remains unchanged in the entire range of ion doses of 3×10¹⁴–1.2×10¹⁷ cm^?2. The process of defect production in the clusters is shifted to higher ion doses compared to that in structurally homogeneous materials. The optical absorption in the π clusters, their concentration in the samples, the tunneling parameters for initial and completely “graphitized” films, and the width of the barrier layer between the clusters were estimated; the width of the band of defect states was determined. It is shown that the known dependence of the optical band gap of the π clusters on their size should be modified for large clusters (E _g ≤1 eV).     

Electrical and optical activation studies of Si-implanted GaN

Comprehensive and systematic electrical and optical activation studies of Si-implanted GaN were made as a function of ion dose and anneal temperature. Silicon ions were implanted at 200 keV with doses ranging from 1×10¹³ cm^?2 to 5×10¹⁵ cm^?2 at room temperature. The samples were proximity-cap annealed from 1050°C to 1350°C with a 500-Å-thick AlN cap in a nitrogen environment. The optimum anneal temperature for high dose implanted samples is approximately 1350°C, exhibiting nearly 100% electrical activation efficiency. For low dose (≤5×10¹⁴ cm^?2) samples, the electrical activation efficiencies continue to increase with an anneal temperature through 1350°C. Consistent with the electrical results, the photoluminescence (PL) measurements show excellent implantation damage recovery after annealing the samples at 1350°C for 20 sec, exhibiting a sharp neutral-donor-bound exciton peak along with a sharp donor-acceptor pair peak. The mobilities increase with anneal temperature, and the highest mobility obtained is 250 cm²/Vs. The results also indicate that the AlN cap protected the implanted GaN layer during high-temperature annealing without creating significant anneal-induced damage.     

ZnO:Al(ZAO)透明导电薄膜的制备及其特性

笔者采用射频磁控溅射工艺、以氧化锌铝陶瓷靶为靶材制备透明导电ZAO薄膜,系统研究了各工艺参数,如氧流量、工作气压、温度、射频功率和退火条件等对其结构和光电特性的影响。实验结果表明:在纯氩气中且衬底温度为300℃时制备的ZAO薄膜经热处理后电阻率降至8.7104 W·cm,可见光透过率在85%以上。X射线衍射谱表明ZAO晶粒具有六角纤锌矿结构且呈c轴择优取向,晶粒垂直于衬底方向柱状生长。     

玻璃–氧化硅复合基板材料的制备及性能

以低相对介电常数的硼硅酸盐玻璃粉末和氧化硅粉末为原料,制备了玻璃–氧化硅复合材料。研究了烧结温度和氧化硅含量对复合材料的电学性能和力学性能的影响。结果表明,当氧化硅质量分数为45%时,玻璃–氧化硅复合材料经840℃、2h的烧结后,其εr为3.8,tanδ为4×10–4,ρv为9.8×1011?·cm,抗弯强度σ为30MPa。另外,该复合材料在100~500℃之间的热膨胀系数为(8.0~10.0)×10–6℃–1。     

Study of structural,electrical and photoconductive properties of F and P co-doped SnO2 transparent semiconducting thin film deposited by spray pyrolysis

Transparent conducting phosphorus–fluorine co-doped tin oxide (SnO₂:(P, F)) thin films have been deposited onto preheated glass substrates using the spray pyrolysis technique by the various dopant quantity of spray solution. The [F/Sn] atomic concentration ratio (x) in the spray solution is kept at value of 0.7 and the [P/Sn] atomic ratio (y) varied at values of 0, 0.001, 0.005, 0.01, 0.02, 0.04, 0.06, and 0.10. The structural, morphological, X-ray diffraction, electrical, optical and photoconductive properties of these films have been studied. It is found that the films are polycrystalline in nature with a tetragonal crystal structure corresponding to SnO₂ phase having orientation along the (110) plane and polyhedrons like grains appear in the FE-SEM image. The average grain size increases with increasing P-dopant concentration. The compositional analysis of FTO:P thin films were studied using EDAX. The Hall effect measurements have shown n-type conductivity in all deposited films. The lowest sheet resistance and highest the carrier concentration about 6.4 Ω/□ and 7.4×10²², respectively, were obtained for the film deposited with y=[P/Sn]=0.01. The films deposited with y=0.04 phosphorus-doped SnO₂:F shows 68% optical transparency. From the photoconductive studies, the P-doped films exhibited sensitivity to incident light especially in y=0.04. The electrical resistivity and carrier concentration vary in rang 6.2×10⁻⁴ to 21.1×10⁻⁴ Ω cm and 7.4×10²² to 1.3×10²² cm⁻³, respectively.     

Electrical and optical properties of Cu2ZnSnS4 grown by a thermal co-evaporation method and its diode application

Cu₂ZnSnS₄ (CZTS) is low cost and constitutes non-toxic materials abundant in the earth crust. Environment friendly solar cell absorber layers were fabricated by a thermal co-evaporation technique. Elemental composition of the film was stated by energy dispersive spectroscopy (EDS). Some optical and electrical properties such as absorption of light, absorption coefficient, optical band gap charge carrier density, sheet resistance and mobility were extracted. Optical band gap was found to be as 1.44 eV, besides, charge carrier density, resistivity and mobility were found as 2.14×10¹⁹ cm⁻³, 8.41×10⁻⁴ Ω cm and 3.45×10² cm² V⁻¹ s⁻¹, respectively. In this study Ag/CZTS/n-Si Schottky diode was fabricated and basic diode parameters including barrier height, ideality factor, and series resistance were concluded using current–voltage and capacitance–voltage measurements. Barrier height and ideality factor values were found from the measurements as 0.81 eV and 4.76, respectively, for Ag/CZTS/n-Si contact.     

(1–x)BiFeO3-xBaTiO3陶瓷的结构与电学性能研究

采用固相反应法制备了(1–x)BiFeO3-xBaTiO3多晶陶瓷样品,研究了 BaTiO3添加对 BiFeO3陶瓷结构、电学性能的影响。结果表明:当 x 由 0 增加到 0.4 时,样品的相结构由三方钙钛矿结构逐渐转变为立方结构,杂相有效消除;漏电流密度从 1.1×10–5A·cm–2下降至 1.1×10–7A·cm–2,相对介电常数提高了 2.6 倍,剩余极化强度增加了近 20 倍。