The large area CdTe thin film samples were used for chloride annealing. The CuCl2/NH4Cl solution was attached on the CdTe surface. After annealing treatment, the CdTe solar cells were prepared. The structure of the thin films and the properties of the CdTe solar cells were tested for studying the effect of the ratio of Cu/Cl, solution concentration and the annealing temperature. At last the performance of CuCl2/NH4Cl annealing cells, ZnTe back contact cells and C:Te,Cu back contact cells were compared. Without back contact layers the efficiency of the CdTe solar cells reached 11.13% with chloride annealing.

Tin oxide films were successfully prepared on glass substrates by radio frequence (RF) magnetron sputtering with a ceramic target under different substrate temperatures. To investigate the influence of substrate temperature on the prepared films, the thickness of as-deposited films was fixed at 240-260nm. Tin oxide films were annealed at 450 degrees C in air ambient for 60min. Structure, optical and electrical properties of as-deposited and annealed films have been studied as a function of film thickness and substrate temperature. The crystallinity of the films is strongly dependent on the film thickness and growth temperature, which in turn has a great effect on the optical and electrical properties of the films. The average transmittance in ultraviolet region, E-g and resistivity of the films are obviously improved after annealing. The stability of the CdS/CdTe solar cells is improved by introducing the high resistance transparent film (HRT).

We present a detailed study on CuxS polycrystalline thin films prepared by chemical bath method and utilized as back contact material for CdTe solar cells.The characteristics of the films deposited on Si-substrate are studied by XRD.The results show that as-deposited CuxS thin film is in an amorphous phase while after annealing,samples are in polycrystalline phases with increasing temperature.The thickness of CuxS thin films has great impact on the performance of CdS/CdTe solar cells.When the thickness of the film is about 75 nm the performance of CdS/CdTe thin film solar cells is found to be the best.The energy conversion efficiency can be higher than 12.19%,the filling factor is higher than 68.82% and the open-circuit voltage is more than 820 mV.

CdS polycrystalline thin films were prepared by close-space sublimation,and then the films were treated at 400 ℃ for Cl-doping.The electrical properties of CdS before and after doping were studied by analyzing the relationship of light/resistance and dark resistance/ temperature.The results show that,under the lighting with different wavelengths,the films have different resistances,and the minimum resistance appears in the vicinity of 500nm wavelength;in the conversion process of dark and light,the effects of doping on the resistance time relaxation are greater;after doping,the dark conductivity increases while activation energy decreases.

It is well known that preparing temperatures and defects are highly related to deep-level impurities. In our studies, the CdTe polycrystalline films have been prepared at various temperatures by close spaced sublimation (CSS). The different preparing temperature effects on CdS/CdTe solar cells and deep-level impurities have been investigated by I—V and C—V measurements and deep level transient spectroscopy (DLTS). By comparison, less dark saturated current density, higher carrier concentration, and better photovoltaic performance are demonstrated in a 580°C sample. Also there is less deep-level impurity recombination, because the lower hole trap concentration is present in this sample. In addition, three deep levels, Ev + 0.341 eV(H4), Ev + 0.226 eV(H5) and EC − 0.147 eV(E3), are found in the 580°C sample, and the possible source of deep levels is analysed and discussed.

采用超声喷雾热解法制备了SnS薄膜,用XRD和SEM等测试手段对薄膜样品的晶体结构和表面形貌进行了表征,并测试了SnS薄膜时光学性能.制备中对比了几种反应前驱液配方和改变沉积温度对SnS薄膜结构、形貌及透过率的影响,得到了如下结果:以N,N-二乙基硫脲+氯化亚锡+甲醇溶液作为前驱液,沉积温度为300℃时,可得到不含有SnO2的单一SnS薄膜.

The CdTe thin films PV module had been studied by measuring the contact resistance between the back contact metal and the front TCO film of the adjacent elementary cells.The "MODULE DESIGN SIMULATOR" software had been used to simulate the effects of the film electronic performance,the integration structure,and the contact elementary cell characteristics on module characteristics.The contact resistance decreases with the increasing of the thickness of Ni film.And the contact resistance increases 1-2 orders of magnitude when the CdTe films were etched by basic frequency laser.The highest efficiency corresponds with the optimized cell width and the width of the notches.The unit cell width,sheet resistance of TCO & CdTe,and TCO/Ni contact resistance have great effect on the property of the module,respectively.With the increasing of TCO sheet resistance,the conversion efficiency firstly increase sharply and then decrease slowly.Increasing the sheet resistance of CdTe will lead to the increasing of both conversion efficiency and fill factor.

In this paper, the AlSb polycrystalline thin films were prepared by vacuum co-evaporation technology and their structural, optical and electrical properties have been studied. XRD results showed that the as-deposited AlSb amorphous thin films transformed to polycrystalline state after annealed in vacuum at temperatures higher than 540°C. The process of phase change was observed to depend on the annealing temperature and the film composition. Some irreversible changes took place in the annealed films during the measurement of the temperature dependence of the film conductance. The conductance activation energy of the film was 0.132 and 0.32 eV during the heating and cooling process, respectively, which suggests the decrease of Sb vacancies in the AlSb film after the heating. Hall effect and optical absorption measurement showed that the AlSb polycrystalline thin films were p-type, indirect bandgap semiconductors with absorption coefficient higher than 8 × 104 cm -1. TCO/CdS/AlSb photovoltaic devices with the local open circuit voltage of over 200 mV have been fabricated.

Cd1-xZnxS thin films were deposited on glass substrates by a vacuum coevaporation method. The structural, compositional, and optical properties of as-deposited Cd0.8Zn0.2S films were investigated using X-ray diffraction (XRD), X-ray fluorescence (XRF), X-ray photoelectron spectroscopy (XPS), and optical transmittance spectrum. The thin films are hexagonal in structure, with strong preferential orientation along the ( 002) planes. The composition of Cd1-xZnxS thin films monitored by a quartz crystal oscillator agrees well with that obtained from XRF and XPS measurements. The optical constants, such as refractive index, single-oscillator energy, dispersion energy, absorption coefficients, and the optical band gap, were deduced by the Swanepoel's method, in combination with the Wemple and DiDomenico single-oscillator model, from the transmission spectrum of Cd0.8Zn0.2S thin films.

In the present paper, SnS thin films were deposited by ultrasonic spray pyrolysis method. The influence of the three different precursor concentrations on the properties of SnS thin films was compared. XRD shows that when precursor solution is thiourea (0.5 mol x L(-1)) + tin tetrachloride (0.5 mol x L(-1)) + deionized water, there are SnS and SnO2 mixed phases; when precursor solution is thiourea (0.6 mol x L(-1)) + tin tetrachloride (0.5 mol x L(-1)) + deionized water, SnS phase is the dominant diffraction peak, although a certain amount of SnO2 phase is contained; when precursor solution is thiourea (0.7 mol x L(-1)) + tin tetrachloride (0.5 mol x L(-1)) + deionized water, thin film after being annealed is single SnS thin film with orthorhombic structure. SEM shows that films are uniform and dense. Furthermore, the particles of films are bigger when thiourea concentration is higher. Transmittance spectrum shows that the influence of precursor concentration on transmittance of thin films is less. Dark I-V and C-V tests of the devices show that junction characteristics of the devices were similar when prepared by three different concentrations of precursor solution, and as the thiourea concentration is higher, the carrier concentration is relatively larger.

The cadmium telluride thin film was deposited on glass substrate at room teperature by RF magnetron sputtering.The film was characterized to show the variation of its properties with the diverse deposition conditions by X-ray diffraction,UV-VIS spectrometer,scanning electrical microscope,etc.The result indicates that the deposition speed increases with the increase of deposition power and decreases with the increase of pressure.As the pressure decreases,the CdTe film's crystallinity gets worse.It is found that the cubic crystalline structure of deposited sample changes to the crystalline hexagonal CdTe phase as the power increased from 100 W to140 W.While the CdTe thin films is deposited under the pressure of 0.3 Pa,with the power of 100 W and at room temperature,the crystallinity is the best and the band gap is 1.45 eV.

The Al/Sb multi-layer thin films were prepared by magnetron sputtering method. The structural, optical and electrical properties of the films before and after annealing have been studied with X-ray diffraction (XRD), X-ray fluorescence (XRF), Hall effect, the temperature dependence of the film dark conductivity and UV-Vis transmission spectra. The XRD results showed that only the Sb polycrystalline peaks were observed in as-deposited films while Al existed in amorphous state. After annealing at 500℃, the films showed AlSb peaks with (111) preferred orientation, which suggested that Al and Sb atoms have combined to form AlSb by interdiffusion. The measurement results of Hall effect indicated that the prepared AlSb films were p-type semiconductors with the carrier concentration of 1019cm-3. The energy band-gap of the AlSb films obtained from UV-Vis data were about 1.64eV. The temperature dependence of the film conductivity showed two stages. In the heating process from 30℃ to 110℃, the conductivity of the film increased slowly with the temperature. In the stage from 110℃ to 260℃, the film conductivity increased more quickly with the temperature. The calculated conductivity activation energy was 0.01eV and 0.11eV, respectively. This result had close relationship with the structural changes of the multi-layer Al/Sb films in the heating process. The obvious photovoltaic effect has been observed in TCO/CdS/AlSb/ZnTe:Cu/Au devices, which demonstrated the potential of AlSb as the absorber layer in solar cells.

Cu would be doped and form deep level centers easily in CdTe solar cells. The deep level centers in ZnTe back contact and graphite back contact CdTe solar cells were studied by deep level transient spectroscopy(DLTS). The electronic density of states on zinc blende CdTe，VCd system and CdTe doping Cu were analyzed with density functional theory. The d-orbital splitting of Cu2+ in C3v and Td fields was obtained. The results show that two deep centers Ev+0206 eV and Ev+0122 eV，respectively，are attributed to substitutional Cu，energy of CdTe is reduced after Cu doping，and Cu could replace Cd.

AlSb polycrystalline thin films were prepared by magnetron sputtering with an improved geometric target, and their structural, electrical and optical properties were studied. The results of XRD measurements suggest that the annealed AlSb thin films are Zinc-blende structure with the average size of about 23～31nm, and the higher temperature promotes the crystallization of the films. The morphology obtained from the AFM measurements reveals that the surfaces of the films are smooth and the particles are uniform with the average size of about 50nm. Hall Effect measurements show that AlSb films are p-type semiconductors and the test of temperature dependence of dark conductivity in vacuum indicates the conductivity activation energys are 0.05eV at low temperature and 0.13eV at a higher temperature. The optical bandgap for a typical AlSb film is 1.52eV, which is indicated from the optical absorption measurements.

本文测试了掺杂石墨浆作背接触层的CdTe薄膜太阳电池的导纳谱,计算得到电池中存在的影响电池性能的缺陷能级及其俘获截面.掺杂石墨浆作背接触层的CdTe薄膜太阳电池中存在三个缺陷能级,其位置E1-Ev分别约为0.34,0.46和0.51 eV,对应的俘获截面分别为2.23x10(-16),2.41x10(-14),4.38x10(-13)cm2.

Polycrystalline CdTe thin films were prepared by close-spaced sublimation (CCS) and were annealed in different condition. The thin films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy(XPS). The content distribution and valence state of all elements after annealing were studied. All results show that the as-deposited CdTe thin films are in a cubic phase and have the preferred orientation in (111) direction. After annealing, the peak intensity of (111), (220), (311) grows and the crystal grains grow up, while the crystal boundary decreases. So the compound probabilities of current carrier decrease, therefore shunt resistance and drain current are improved. From detailed analysis of X-ray photoelectron data, it is proposed that tellurium oxides present and its content reduces with depth increasing and that there are TeCl2O building blocks.

Deposition of Sb2Te3 thin films on soda-lime glass substrates by coevaporation of Sb and Te is described in this paper. Sb2Te3 thin films were characterized by x-ray diffraction (XRD), x-ray fluorescence (XRF), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), electrical conductivity measurements, and Hall measurements. The abnormal electrical transport behavior occurred from in situ electrical conductivity measurements. The results indicate that as-grown Sb2Te3 thin films are amorphous and undergo an amorphous-crystalline transition after annealing, and the posttreatment can effectively promote the formation of Sb-Te bond and prevent oxidation of thin film surface.

In this research, the CdTe polycrystalline films are prepared at various temperatures by close-spaced sublimation. The experiment was conducted to investigate how difference in preparation temperature effects on CdTe/CdS solar cells by the characteration of I - V , C - V curves and deep level transient spectroscopy. The result shows that the difference of temperatures has some effect on I sc and FF, but not on V oc . The samples prepared at 580℃ have lowest dark saturated current density, higher carrier concentration and the photovoltaic performance is preferable. The response of deep-level impurities in CdTe films is unchanged with temperature and frequency, but the sample prepared at 580℃ has less deep-level impurity recombination because of lower hole trap concentration. Then, the CdS/CdTe solar cells with large area of 300 mm×400 mm have efficiency reaching 82% by improving the uniformity of temperature field.

In this paper,the polycrystalline Cd1-xZnxS thin films were prepared by the vacuum co-evaporation method and structural,optical,and electrical properties of Cd_(1-x)Zn_xS(x=0.88) thin films were investigated.Cd_(1-x)Zn_xS(0x≤0.9) thin films were hexagonal structure and showed highly preferential orientation.The composition of Cd_(1-x)Zn_xS thin films determined from Vegard law and quartz crystal oscillation method agrees with that determined from the X-ray fluorescence spectra.Optical absorption edge of optical transmittance for Cd1-xZnxS thin films exhibits a blue shift with the increase of the zinc content,which indicates that optical energy gap can be tuned between 2.44-3.78eV.Finally,the values of dark conductivity for Cd_(1-x)Zn_xS thin films at various temperatures were measured,and conductivity activation energies were calculated.

CdTe thin film solar cells with a doped-graphite paste back contact layer were studied using admittance spectroscopy technology. The positions and the capture cross sections of energy level in the forbidden band were calculated, which are the important parameters to affect solar cell performance. The results showed that there were three defects in the CdTe thin films solar cells with the doped-graphite paste back contact layer, whose positions in the forbidden band were close to 0.34, 0.46 and 0.51 eV, respectively above the valence band, and capture cross sections were 2.23×10 −16 , 2.41×10 −14 , 4.38×10 −13 cm 2 , respectively.