Effects of the Cr doping on structure and optical properties of ZnO thin films

Cr-doped ZnO thin films are prepared on glass substrates by the magnetron sputtering technique. An X-ray diffraction (XRD) is used to analyze the structural properties of the thin films. It indicates that all the thin films have a preferential c-axis orientation. The peak position of the (002) plane shifts to the higher 2θ value, and the peak intensity decreases with the increase of Cr doping. The results of the scanning electron microscopy (SEM) show that the surface morphology becomes loose with the incre...     

Structural and optical properties of Cu2FeSnS4 thin film synthesized via a simple chemical method

Cu₂FeSnS₄ thin film, with potential as an effective photovoltaic absorber, was prepared by sulfurizing a (Cu,Sn)S/FeS-structured precursor prepared via successive ionic layer absorption and reaction combined with chemical bath deposition. X-Ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and UV-vis-NIR absorbance measurements showed that the Cu₂FeSnS₄ thin film exhibits large agglomeration of rod-shaped grains, a bandgap of E_g=1.22 eV, and a high optical absorption coefficient (>10⁴ cm⁻¹).     

sol-gel 法制备ATO薄膜的结构与光学性能研究

采用sol-gel法在玻璃衬底上制备ATO(SnO2∶Sb)薄膜,并用XRD、SEM、紫外-可见光谱和光致发光对薄膜进行了表征,研究了ATO薄膜的结构和光学性能。结果表明:ATO薄膜微晶晶相与SnO2一致,仍然是四方金红石结构;ATO薄膜在可见光区的透过率超过80%,当r(Sb∶Sn)为0.15时,ATO薄膜的透过率最高达87%;ATO薄膜在344～380nm处有一个很强的紫外-紫光发射带,随着Sb掺杂量的增加,发射峰逐渐变强,在r(Sb∶Sn)为0.25时,发射峰相对强度达302.4。     

Effects of Sb,Zn doping on structural,electrical and optical properties of SnO2 thin films

Highly transparent, low resistive pure and Sb, Zn doped nanostructured SnO₂ thin films have been successfully prepared on glass substrates at 400° C by spray pyrolysis method. Structural, electrical and optical properties of pure and Sb, Zn doped SnO₂ thin films are studied in detail. Powder X-ray diffraction confirms the phase purity, increase in crystallinity, size of the grains (90–45 nm), polycrystalline nature and tetragonal rutile structure of thin films. The scanning electron microscopy reveals the continuous change in surface morphology of thin films and size of the grains decrease due to Sb, Zn doping in to SnO₂. The optical transmission spectra of SnO₂ films as a function of wavelength confirm that the optical transmission increases with Sb, Zn doping remarkably. The optical band gap of undoped film is found to be 4.27 eV and decreases with Sb, Zn doping to 4.19 eV, 4.07 eV respectively. The results of electrical measurements indicate that the sheet resistance of the deposited films improves with Sb, Zn doping. The Hall measurements confirm that the films are degenerate n-type semiconductors.     

Structural,optical and electrical properties of Cu2FeSnSe4 and Cu(In,Al)Se2 thin films

Cu-based semiconductors Cu₂FeSnSe₄ (CFTSe) and Cu(In, Al)Se₂ (CIAS) have been fabricated using radio-frequency magnetron sputtering combined with rapid thermal selenization processing. For CFTSe, the heating rate ranging from 60 to 150 °C/min results in a difference in structure, morphology and optical properties. Thin film exhibits a pure phase structure, smooth surface and a band gap of 1.19 eV as the heating rate elevated to 90 °C/min. Furthermore, the CFTSe thin film selenized at 90 °C/min own the smallest value of cell volume compared with the others samples, which represents a more stable structure. In terms of the other Cu-based material CIAS, three different selenization pressures, i.e., 1, 5 and 10 Torr, have been employed for CIAS preparation. Thin film transforms into single phase with dense morphology along with the pressure of 1 Torr. The diverse band gap of CIAS thin films from 1.34 to 2.18 eV attribute to two reasons: (i) the various Al content will affect the hybridization degree of Al–Se, and finally tunes the band structure, (ii) amounts of CuSe has a certain degree of effect on the band gap of the CIAS. In addition, the electrical properties of CFTSe and CIAS are also researched with the open circuit voltage (V_oc) of 94 and 365 mV, respectively, signifying potential applications of CFTSe and CIAS for the thin film solar cells.     

Influence of Mn doping on structural,optical and electrical properties of CdO thin films prepared by cost effective spray pyrolysis method

Transparent and conducting cadmium oxide (CdO) and manganese doped CdO (Mn: CdO) thin films were deposited using a low cost spray pyrolysis method on the glass substrate at 300 °C. For Mn doping, various concentrations of manganese acetate (1–3 wt%) was used in the spraying precursor solution. The structural, electrical and optical properties of CdO and Mn: CdO films were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscope (AFM), UV–vis and Hall measurement. X-ray diffraction study reveals that the CdO and Mn: CdO films are possessing cubic crystal structures. SEM and AFM studies reveal that the grain size and roughness of the films are increased with increasing Mn doping concentration. Optical transmittance spectra of the CdO film decreases with increasing doping concentration of manganese. The optical band gap of the films decreases from 2.42 eV to 2.08 eV with increasing concentration of manganese. A minimum resistivity of 1.11×10⁻³ Ω cm and maximum mobility of 20.77 cm² V⁻¹ s⁻¹ is achieved for 1 wt% of manganese doping.     

Optical properties of ZnO thin films prepared by sol-gel process

The present study focused on ZnO thin films fabricated by sol-gel process and spin coated onto Si (1 0 0) and quartz substrates. ZnO thin films have a hexagonal würtzite structure with a grain diameter about 50 nm. Optical properties were determined by photoluminescence (PL) and absorption spectroscopy. The absorption spectrum is dominated by a sharp excitonic peak at room and low temperatures. At room temperature, two transitions were observed by PL. One near to the prohibited energy band in ultraviolet (UV) region and the other centered at 640 nm, characteristic of the electronic defects in the band-gap. The spectrum at 6 K is dominated by donor-bound exciton lines and donor-acceptor pair transition. LO-phonon replica and two-electron satellite transitions are also observed. These optical characteristics are a signature of high-quality thin films.     

硫化法制备ZnS薄膜的结构和光学性能研究

采用直流反应磁控溅射法,在玻璃衬底上沉积了ZnO薄膜,然后在H2S气氛和500℃温度下退火制备了六方ZnS薄膜。利用X射线衍射仪(XRD)、UV-VIS分光光度计、扫描电子显微镜(SEM)对样品进行了表征。结果表明:ZnO经0.5 h硫化就能全部生成ZnS,适当提高硫化时间可改善ZnS的结晶性,但硫化时间超过2 h后,结晶性会有所降低;所有制得ZnS薄膜都沿c轴择优生长,其晶粒明显比ZnO更大。此外,这些ZnS薄膜在500~1 100nm波长范围内的光透过率均高达约75%,带隙为3.65~3.70 eV。     

溶胶-凝胶旋涂法制备In掺杂ZnO薄膜结构和光学性能的研究

采用溶胶-凝胶(sol-gel)旋涂法在常规玻璃衬底 上生长了In掺杂浓度分别为1at%、2at%、3at%、4at%、5at%的ZnO薄膜。借助X射线衍射仪(X RD)、扫描电子显微镜(SEM)、紫外- 可见分光光度计(UV-Vis)对样品的晶粒生长、结构以及光学性能进行表征。结果如下:所 制 备的薄膜均沿(002)方向择优生长,且随着In³⁺掺杂浓度增加 ,衍射峰的峰型及半高宽均呈 先降低后升高的趋势;In³⁺掺入后,ZnO薄膜晶粒由原来的六边形状发展成类似蠕虫 状,同 时粒径变小且大小不一;与本征样品相比,掺杂后的ZnO光透过率提高了10%,且吸收边向短 波长方向偏移,同时随着In³⁺的掺入,薄膜的光学带隙值从3.49 eV增加到3.80 eV。当In³⁺掺 杂浓度为4at%时,薄膜(002)峰的峰形最为尖锐、峰值最大,晶粒较为均匀、 晶格间距更小,光透过率最高,光学带隙值相对较大为3.77 eV。     

低温磁控溅射制备CdS薄膜的结构和光学特性

用磁控溅射的方法在透明导电氧化物衬底上制备了CdS薄膜,制备时的衬底温度为30~200℃.X射线衍射测试结果表明在这一条件下制备的CdS薄膜是六角纤锌矿的多晶结构.扫描电子显微镜结果显示薄膜具有较好的晶体质量,这一结论也和拉曼光谱、紫外-可见吸收光谱、光致发光光谱的结果一致.拉曼光谱显示CdS薄膜内部的压应力随着制备温度的提高而增大.     

sol-gel法制备ZAO薄膜的结构与光学性能研究

采用溶胶—凝胶法在普通玻璃衬底上制备了ZAO(ZnO:A1)薄膜,利用XRD、SEM、紫外—可见光谱和光致发光光谱对所制备的AZO薄膜进行了表征,研究了ZAO薄膜的结构和光学性能.结果表明:ZAO薄膜的微晶晶相与ZnO一致,且具有c轴择优取向;ZAO薄膜在可见光区的透过率超过了88％,在350～575 nm范围内有强的...     

ZnO薄膜的结构与光学性能研究

采用sol-gel法在石英衬底上制备了ZnO薄膜,通过改变溶胶浓度、涂敷层数及退火温度,研究了ZnO薄膜的形貌、结构性能及光学性能。结果表明,薄膜具有六方纤锌矿结构,表面均匀致密,晶粒大小在25～35nm之间,Zn含量为0.8mol/L的溶胶经旋涂并在500℃下退火1h后可获得最高的可见光透射率,平均透射率约为94%。获得的ZnO薄膜的光学带隙在3.27～3.29eV之间。     

射频磁控溅射制备的ZnMgO薄膜结构和光学性能

采用射频磁控溅射法,在石英衬底上制备了Zn1-xMgxO(x=0.00～0.16)薄膜。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见分光光度计和光致发光(PL)光谱等分析了薄膜的结构、形貌和光学特性。结果表明:当x≤0.10时薄膜保持六角纤锌矿结构,而x=0.16时已出现MgO立方相;所有薄膜晶粒大小均匀,在100～150 nm之间;透光率在80%以上;薄膜带隙Eg与Mg含量呈线性关系;薄膜PL谱由较弱的紫外发光峰和较强的可见发光带组成,随Mg含量的增加紫外发光峰蓝移。     

Photoelectric properties of Cu2ZnSnS4 thin films deposited by thermal evaporation

正Sn/Cu/ZnS precursor were deposited by evaporation on soda lime glass at room temperature,and then polycrystalline thin films of Cu_2ZnSnS_4(CZTS) were produced by sulfurizing the precursors in a sulfur atmosphere at a temperature of 550℃for 3 h.Fabricated CZTS thin films were characterized by X-ray diffraction,energy dispersive X-ray spectroscopy,ultraviolet-visible-near infrared spectrophotometry,the Hall effect system,and 3D optical microscopy.The experimental results show that,when the ratios of[Cu]/([Zn]+[Sn]) and[Zn]/[Sn]in the CZTS are 0.83 and 1.15,the CZTS thin films possess an absorption coefficient of larger than 4.0 x 10~4 cm~(-1) in the energy range 1.5-3.5 eV,and a direct band gap of about 1.47 eV.The carrier concentration,resistivity and mobility of the CZTS film are 6.98 x 10~(16) cm~(-3),6.96Ω-cm,and 12.9 cm~2/(V-s),respectively and the conduction type is p-type.Therefore,the CZTS thin films are suitable for absorption layers of solar cells.     

Influence of Cu doping on physical properties of sol-gel processed SnS thin films

Copper-doped tin sulfide thin films (Cu-SnS) with different Cu doping concentrations were prepared by using the spin coating technique and their structural, electrical, and optical properties were studied. All the prepared films were polycrystalline and exhibited diffraction peaks corresponding to orthorhombic SnS with the preferred (111) orientation. The XRD spectra revealed improvement in the preferential orientation and crystalline quality with up to 4% Cu doping concentration, whereas Cu doping concentrations above 4% deteriorate the preferential orientation and crystalline quality. It has been observed that upon Cu doping the band gap decreased significantly from 1.46 eV (pure SnS) to 1.37 eV (4% of Cu-doped SnS). Hall measurements revealed the p-type semiconducting nature of the SnS thin films. The observations revealed that doping of SnS with Cu causes a noticeable drop in the room-temperature resistivity value from 10⁵ Ω-cm for pure SnS to 10³ Ω-cm for 4% Cu-doped SnS.     

Cu掺杂对CoFe_2O_4结构与磁性能的影响

为了系统地研究Cu掺杂对于CoFe_2O_4结构与磁性能的影响及其影响机制,采用柠檬酸-溶胶凝胶法制备了Co_(1–x)Cu_xFe_2O_4(x=0,0.2,0.4,0.6,0.8,1)磁性纳米颗粒。分别用X射线衍射仪,透射电子显微镜,振动样品磁强计对样品的晶体结构、形貌、磁学性质进行了表征和测试。结果发现所制备的钴铜铁氧体的纳米颗粒直径在50~60 nm,适量的Cu~(2+)掺杂,铜钴铁氧体依然保持面心立方结构,且可以有效降低其饱和磁感应强度和居里温度。但是掺杂量达到x=0.8后,会引起Jahn Teller效应,铜钴铁氧体发生晶格畸变,由面心立方相转变为面心四方相,饱和磁感应强度、居里温度随之增加。     

Effects of discharge power on the structural and optical properties of TGZO thin films prepared by RF magnetron sputtering technique

The transparent semiconductors of Ti and Ga-incorporated ZnO (TGZO) thin films were prepared by radio frequency (RF) magnetron sputtering onto glass substrates. The effects of discharge power on the physical properties of thin films are studied. Experimental results show that all nanocrystalline TGZO thin films possess preferential orientation along the (002) plane. The discharge power significantly affects the crystal structure and optical properties of thin films. When the discharge power is 200 W, the TGZO thin film has the optimal crystalline quality and optical properties, with the narrowest full width at half-maximum (FWHM) of 1.76´10-3 rad, the largest average grain size of 82.4 nm and the highest average transmittance of 84.3% in the visible range. The optical gaps of thin films are estimated by the Tauc’s relation and observed to increase firstly and then decrease with the increase of the discharge power. In addition, the optical parameters, including refractive index, extinction coefficient, dielectric function and dissipation factor of the thin films, are determined by optical characterization methods. The dispersion behavior of the refractive index is also analyzed using the Sellmeier’s dispersion model.     

Magnetic properties of ZnO:Cu thin films prepared by RF magnetron sputtering

ZnO films and ZnO:Cu diluted magnetic semiconductor films were prepared by radio frequency magnetron sputtering on Si (111) substrates, with targets of ZnO and Zn0.99Cu0.01 O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.     

射频磁控溅射法制备ZnO:Cu薄膜的磁性研究

ZnO films and ZnO：Cu diluted magnetic semiconductor films were prepared by radio frequency mag-netron sputtering on Si （111） substrates, with targets of ZnO and Zn0.99Cu0.01O, respectively. The plasma emission spectra were analyzed by using a grating monochromator during sputtering. The X-ray photoelectron spectroscopy measurements indicate the existence of Zni defect in the films, and the valence state of Cu is 1＋. The X-ray diffraction measurements indicate that the thin films have a hexagonal wurtzite structure and have a preferred orientation along the c-axis. The vibrating sample magnetometer measurements indicate that the sample is ferromagnetic at room temperature, and the origin of the magnetic behavior of the samples is discussed.