• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    Influence of deposition power on the optical and electrical performance of sputtered gallium-magnesium co-doped zinc oxide thin films

    2023-11-07 09:15:40ZHONGZhiyouWANXinGUJinghuaLONGHaoYANGChunyongCHENShoubu
    關(guān)鍵詞:時(shí)所光學(xué)薄膜

    ZHONG Zhiyou,WAN Xin,GU Jinghua,LONG Hao,YANG Chunyong,CHEN Shoubu

    (1 College of Electronic Information Engineering,South-Central Minzu University,Wuhan 430074,China;2 Hubei Key Laboratory of Intelligent Wireless Communications,South-Central Minzu University,Wuhan 430074,China;3 Experimental Teaching and Engineerring Training Center,South-CentralMinzu University,Wuhan 430074,China)

    Abstract The transparent conductor thin films of gallium-magnesium co-doped zinc oxide(ZnO:Ga-Mg)were deposited by magnetron-sputtering process.The deposition power dependence of structural,morphological,optical and electrical properties of the thin film was characterized by various techniques.The experimental results indicate that all the thin films have hexagonal wurtzite structure with highly c-axis preferred orientation along the(002)plane,and the deposition power strongly affects the properties of ZnO:Ga-Mg thin films.The thin film prepared at the deposition power of 150 W exhibits the best crystallinity quality and photoelectric properties,with the highest average visible transmittance of 92.2%,the lowest resistivity of 1.18×10-3 Ω·cm,the maximum figure of merit of 1.04×104 Ω-1·cm-1,and the minimum lattice strain of 1.95×10-3 and dislocation density of 1.17×1015 m-2.The optical constants of the thin films were obtained by the optical characterization methods.The optical dispersion behavior of the thin films was studied in terms of the single-oscillator Wemple-DiDomenico(WDD)model,and the oscillator parameters,non-linear optical constants and optical energy-gaps were achieved.The results demonstrate that the deposition power is one of the most important processing parameters to affect the structure,optical and electrical properties of ZnO:Ga-Mg thin films.

    Keywords ZnO;thin films;doping;photoelectric properties

    Gallium-doped zinc oxide(ZnO:Ga)is a promising transparent conductor material which has numerous applications in modern technologies such as organic light emitting diodes(OLEDs)[1-2],flat panel displays(FPDs)[3-4],thin film transistors(TFTs)[5-6],photovoltaic cells(PVCs)[7-8],gas sensitive devices[9-10]and ultraviolet(UV)photodetectors[11-13].Besides good electrical conductivity and high visible light transparency,the ZnO:Ga thin films have a variety of advantages,such as material abundance,non-toxicity,low manufacture cost,high exciton binding energy(about 60 meV at room temperature),broad direct energy-gap(about 3.3 eV at room temperature)and excellent chemical-stability under hydrogen plasma,as compared to the tin-doped indium oxide(In2O3:Sn)thin films[14-17].In order to further improve the optical and electrical properties of ZnO:Ga thin films,the codoping process with two elements have been used.Up to now,the titanium-gallium(Ti-Ga),aluminumgallium(Al-Ga),gallium-zirconium(Ga-Zr),galliumindium(Ga-In),boron-gallium(B-Ga),galliumfluorine(Ga-F),magnesium-gallium(Mg-Ga)and nickel-gallium(Ni-Ga)co-doping cases have been reported[18-27].However,few reports have been devoted to the non-linear optical properties and optical dispersion behavior of the co-doped ZnO thin films.

    In this work,the Ga-Mg co-doped ZnO(ZnO:Ga-Mg)thin films were prepared by radio-frequency(RF)magnetron-sputtering process under various deposition powers.The dependence of structure,morphology,photoelectric and non-linear optical properties of the thin films on power was investigated in detail.In addition,the optical constants of the thin films were obtained using the optical characterization methods,and the optical dispersion behavior was studied in terms of the single-oscillator Wemple-DiDomenico(WDD)model.

    1 Experimental

    A quartz glass was employed as the transparent substrate,and a ceramic target(ZnO:95 wt%,Ga2O3:3 wt%,MgO:2 wt%,4N in purity)was used as the sputtering source material.The ZnO:Ga-Mg samples were prepared on the quartz glass substrates by RF magnetron-sputtering system(13.56 MHz).The base pressure in deposition chamber was kept blow 2.25×10-4Pa and high purity argon gas(5N in purity)was used as the working gas.Prior to the ZnO:Ga-Mg samples deposition,the pre-sputtering for 20 min was conducted in order to clean contamination on the ceramic target surface.The ZnO:Ga-Mg samples were prepared under the following processing parameters:7.5 cm of target-substrate distance,300 ℃ of substrate temperature,3.5 Pa of gas pressure and 40 min of sputtering time.In order to investigate the effect of deposition power on the properties of ZnO:Ga-Mg thin films,the power was controlled from 110 to 170 W.

    The thickness of the ZnO:Ga-Mg thin films was measured by an Alpha-step 500 type surface profiler.The surface morphology of the thin films was observed by a JSM-6700F type scanning electron microscope(SEM).The electrical properties of the thin films were investigated at room temperature using a RH-2035 type four-point probe measurement system.The X-ray diffraction(XRD)patterns of the thin films were characterized with a D8-Advanced type diffractometer using standard Cu Kα source(wavelengthλ=0.15406 nm).The optical transmittance(T)of the thin films were measured at room temperature by using a TU-1901 type double beam UV-visible spectrophotometer.The optical constants of the ZnO:Ga-Mg thin films were obtained from the measured transmittance data using the method of optical spectrum fitting[28].All measurements were performed in ambient air.

    2 Results and discussion

    Figure 1 shows the XRD patterns of the standard ZnO powder(PDF 036-1451)and the ZnO:Ga-Mg samples prepared at various powers.From the figure,we note that these XRD peaks of the investigated samples can be assigned to ZnO according to PDF 036-1451 card.All the investigated samples exhibit a dominant(002)peak with slight(101)and(004)peaks,indicating that the ZnO:Ga-Mg thin films have hexagonal wurtzite structure of ZnO with preferredcaxis orientation along the(002)plane,regardless of power.Also,no diffraction peaks from other impurities can be detected from Figure 1,which indicates that all the ZnO:Ga-Mg thin films in this work do not have any phase segregation or secondary phase formation.Similar results have been reported by other researchers who investigated the structural properties of ZnObased thin films[18,21,29-30].

    圖1 PDF 036-1451和不同功率時(shí)所制備薄膜的XRD圖譜Fig.1 XRD patterns of PDF 036-1451 and the thin films prepared at various powers

    The intensity of(002)diffraction peak(I(002))for the ZnO:Ga-Mg samples as a function of power is shown in Figure 2a.As can be seen,the value ofI(002)rises first and thereafter drops with the increment of power.The ZnO:Ga-Mg thin film deposited at the power of 150 W presents the highest intensity of(002)diffraction peak.The degree of preferred(002)orientation of the ZnO:Ga-Mg thin films was quantified by means of the orientation factor(P(002))[31]:

    圖2 不同功率時(shí)所制備薄膜的I(002)和P(002)數(shù)值Fig.2 The values of I(002) and P(002) for the thin films prepared at various powers

    whereI(002)is the intensity of(002)diffraction peak,the subscripth,kandlare Miller indices,I(hkl)denotes the diffraction intensity of the(hkl)plane,andNis the number of the diffraction peaks.Figure 2b shows the variation ofP(002)with power for the ZnO:Ga-Mg thin films.It is found that with increasing power from 110 to 170 W,theP(002)value raises first and subsequently falls.When the power is 150 W,the maximumP(002)value can be obtained,indicating that the ZnO:Ga-Mg sample has the highestc-axis preferred orientation when the power is 150 W.

    The mean particle size(Dm)of the ZnO:Ga-Mg samples was evaluated using the Debye-Scherrer formula[31-32]:

    whereθis the Bragg’s diffraction angle,βis the fullwidth at half-maximum(FWHM,in radians)of(002)diffraction peak,andλdenotes the wavelength of XRD measurement used(λ=0.15406 nm).The lattice strain(ε0)and the dislocation density(δ0)can be obtained by means of the following relationships[33-34]:

    whereDmrepresents the mean particle size,βis the value of FWHM in radians,θdenotes the Bragg’s angle,andλis the wavelength of X-ray used.Figure 3 shows the variation in theβ,Dm,ε0andδ0values of the investigated thin films as a function of power.It can be noticed from Figure 3 that with rising power from 110 to 170 W,the values ofβ,ε0andδ0increase in advance and then fall,but theDmtakes on an opposite trend.When the power is 150 W,the ZnO:Ga-Mg thin film exhibits the optimum crystallinity quality and structural properties,with the narrowestβ(4.91×10-3rad),the largestDm(29.3 nm),the lowestε0(1.95×10-3)and the minimumδ0(1.17×1015m-2),respectively.This result demonstrates that the grain growth and structural properties of the ZnO:Ga-Mg thin films are subjected to the deposition power.

    圖3 不同功率時(shí)所制備薄膜的β,Dm,ε0和δ0數(shù)值Fig.3 The values of β,Dm,ε0 and δ0 for the thin films prepared at various powers

    Figure 4 presents the dependence of optical transmittanceTon wavelengthλfor the ZnO:Ga-Mg samples prepared at various powers.As can be seen,all theT-λcurves exhibit an interference pattern where the transmittance falls rapidly at the edge of the bands,which indicates excellent film crystallinity and low surface roughness.Also,the absorption edge is observed to blue shift firstly with the increasing power from 110 to 150 W and then red shift from 150 to 170 W,as shown in the inset of Figure 4.The power dependence of the mean transmittance(Tm)in the visible wavelength range for the ZnO:Ga-Mg samples is presented in Figure 5a.Note that theTmvalue exceeds 85.7% for the investigated samples regardless of power,which indicates that all the ZnO:Ga-Mg thin films possess high transparency in the visible light region.The highest value(92.2%)ofTmfor the ZnO:Ga-Mg sample can be achieved when the power is 150 W.The enhancement of optical transmittance may be caused by the improvement of crystallinity quality and structural properties of the ZnO:Ga-Mg thin film.

    圖4 不同功率時(shí)所制備薄膜的T-λ曲線Fig.4 The curves of T-λ for the thin films prepared at various powers

    圖5 不同功率時(shí)所制備薄膜的Tm,ρ和FM數(shù)值Fig.5 The values of Tm,ρ and FM for the thin films prepared at various powers

    In order to quantify the photoelectric properties of the ZnO:Ga-Mg transparent conductor oxide (TCO)thin films,the figure of merit(FM)was introduced.TheFMis defined by the following relation[35-36]:

    whereρdenotes the resistivity of the investigated sample,andTmis the average transmittance in the visible range.The power dependence ofρa(bǔ)ndFMfor the ZnO:Ga-Mg samples is shown in Figure 5.It is observed from Figure 5b that theρfalls firstly with the rising power from 110 to 150 W and then increases from 150 to 170 W.The minimumρ(1.18×10-3Ω·cm)of the ZnO:Ga-Mg sample can be obtained when the power is 150 W.The optimalρvalue in this work is comparable to the results of previous studies.For the ZnO-based thin films deposited by RF-sputtering technique,the lowestρvalues were reported to be ranging from 7.23×10-4to 1.52×10-3Ω·cm[19,37-38].Note also from Figure 5c that theFMvalues are found to be 1.26×103,2.49×103,1.04×104and 1.67×103Ω-1·cm-1for the ZnO:Ga-Mg samples fabricated at the power of 110,130,150 and 170 W,respectively.Clearly,theFMraises first and subsequently falls with the increment of power,the ZnO:Ga-Mg thin film deposited at the power of 150 W exhibits the maximumFMvalue,indicating that the optimum deposition power is 150 W for preparing ZnO:Ga-Mg thin film in the present work.

    The direct optical energy-gap()of the ZnO:Ga-Mg thin films was evaluated by using the Tauc’s relation in the region of high absorption[39-40]:

    圖6 不同功率時(shí)所制備薄膜的(αhν)2-hν曲線Fig.6 The curves of(αhν)2-hν for the thin films prepared at various powers

    wherehis Planck’s constant,νis the photon frequency,Bis an energy-independent constant,tfis the film thickness,andαis the absorption coefficient of the thin film[41-42].Figure 6 shows the (αhν)2vs.hνplots of the ZnO:Ga-Mg samples prepared at various powers.As can be seen,a good straight line can be obtained in the band edge region for all the investigated thin films.The straight-line portion of the curve gives the direct optical energy-gapwhen extrapolated to zero((αhν)2=0).The values ofare evaluated to be ranging from 3.41 to 3.49 eV for the ZnO:Ga-Mg samples prepared at various powers.Obviously,the obtainedvalues of all the ZnO:Ga-Mg thin films are larger than that of standard ZnO sample(3.30 eV)[18,43].The broadening inof the ZnO:Ga-Mg thin films mainly be attributed to the Burstein-Moss(B-M)effect[44-47].Similar results have been observed by many researchers who studied the optical properties of ZnObased thin films[47-50].

    Based on the measured transmittance,the optical constants including extinction coefficient(k)and refractive index(n)of the ZnO:Ga-Mg thin films were obtained by the method of optical spectrum fitting[28],and the dependence ofkandnonλfor all the samples is shown in Figure 7.It can be seen from Figure 7a that thekvalues of the investigated samples are very small at long wavelength region,which indicates that all the investigated thin films have high visible transparency.Similar to thek-λcurves,thengradually falls with raisingλfor all the ZnO:Ga-Mg samples.The result suggests that all the ZnO:Ga-Mg thin films exhibit the normal dispersion characteristics in the visible wavelength range[31].For the ZnO:Ga-Mg samples deposited at the power of 110,130,150 and 170 W,the values ofkandnare 1.16×10-2,1.87;8.93×10-3,1.96;3.54×10-3,1.91;and 8.45×10-3,1.94 atλ=450 nm,respectively.The result is in agreement with the previously reported works[51-53].

    圖7 不同功率時(shí)所制備薄膜的k-λ和n-λ曲線Fig.7 The curves of k-λ and n-λ for the thin films prepared atvarious powers

    The refractive index dispersion behavior of the ZnO:Ga-Mg samples was studied according to the single-oscillator WDD model as follows[54-55]:

    whereλis the wavelength of incident light,hdenotes Planck’s constant,cis the light speed,andE,EdandEoare the incident photon energy,the dispersion energy and the single-oscillator energy,respectively.The dependence of (n2-1)-1onE2for the ZnO:Ga-Mg samples prepared at various powers is shown in Figure 8.As can be seen,the data of all the investigated thin films can be fitted into straight lines,indicating that the single-oscillator WDD model is applicable to the ZnO:Ga-Mg samples in this work.TheEdandEoof all the ZnO:Ga-Mg thin films can be deduced from the slopeand intercept(Ed-1Eo)on the vertical axis.The lattice dielectric constant(εL),the static refractive index(n0),theM-1andM-3moments of the optical spectra were obtained using the following equations[56]:

    whereEois the single-oscillator energy,andEdis the dispersion energy.Table 1 lists the values ofEd,Eo,n0,εL,M-1andM-3for all the ZnO:Ga-Mg thin films.TheEovalues can be found to range from 6.07 to 6.80 eV,andEdfrom 11.79 to 14.43 eV for the ZnO:Ga-Mg samples deposited at various powers.In compared with theEd,theEochanges in a very narrow range.Also,it is observed from Table 1 that the deposition power significantly affects the optical parameters of the ZnO:Ga-Mg thin films.

    The third-order non-linear optical susceptibility(χ(3)),the non-linear refractive index(n2)and the non-linear absorption coefficient(α2)of the ZnO:Ga-Mg thin films can be obtained using the following formulae[57-58]:

    表1 不同功率時(shí)所制備薄膜的光學(xué)參數(shù)Tab.1 The optical parameters of the thin films prepared at various powers

    圖8 不同功率時(shí)所制備薄膜的(n2-1)-1-E2曲線Fig.8 The curves of(n2-1)-1-E2 for the thin films prepared at various powers

    whereA=1.7×10-10esu is a constant,cis the speed of light,λis the wavelength of incident light,andnis the refractive index of the thin films.Figure 9 shows the variation in theχ(3),n2andα2values of the ZnO:Ga-Mg thin films as a function of power.Note from Figure 9a that theχ(3)raises rapidly withλdecrease until it reaches a maximum value,and it drops slowly withλincrease until it reaches a constant value for higher wavelengths.In addition,the deposition power has a great influence on theχ(3)in the ultraviolet region,and little influence on theχ(3)in the visible and near-infrared range of the investigated thin films.From Figure 9,we can observe that the variation ofn2andα2follow the similar trend asχ(3)for all the ZnO:Ga-Mg thin films,and the values ofn2andα2are also subjected to the deposition power.When wavelengthλ=450 nm,corresponding to the power of 110,130,150 and 170 W,the values ofχ(3),n2andα2are 2.71×10-13,5.45×10-12,8.49×10-13;4.38×10-13,8.45×10-12,1.26×10-12;3.19×10-13,6.31×10-12,9.73×10-13;4.01×10-13esu,7.78×10-12m2W-1,1.17×10-12mW-1,respectively.The result is in agreement with the data obtained by Aida et al.who studied the optical properties of the sputtered Sm-doped ZnO thin films[58].

    圖9 不同功率時(shí)所制備薄膜的χ(3)-λ,n2-λ和α2-λ曲線Fig.9 The curves of χ(3)-λ,n2-λ and α2-λ for the thin films prepared at various powers

    3 Conclusion

    The TCO thin films of ZnO:Ga-Mg were prepared by magnetron sputtering.The effects of sputtering power on the microstructural,electrical and optical characteristics of the deposited films were investigated.The XRD analysis results show that all the deposited films have hexagonal wurtzite structure with highlycaxis preferred orientation along the(002)plane regardless of the sputtering powers.When the sputtering power is 150 W,the ZnO:Ga-Mg thin film possesses the best crystal quality and photoelectric properties,with the minimum resistivity,dislocation density and lattice strain,and the maximum figure of merit,average visible transmittance and mean particle size.The optical constants of all the deposited films were determined by the method of optical spectrum fitting from the measured transmittance data.It is observed that the refractive index and extinction coefficient tend to reduce with the increment of wavelength.Meanwhile,the dispersion behavior of the refractive index was analyzed by means of the single-oscillator WDD model,and the optical parameters including direct energygap,single-oscillator energy,dispersion energy,the first order of moment,the third order of moment,static refractive index and lattice dielectric constant were achieved.In addition,the dependence of nonlinear optical properties of the deposited films on sputtering power were also investigated in detail.The results demonstrate that the sputtering power is one of the most important deposition parameters to affect the microstructure,optical and electrical properties of ZnO:Ga-Mg TCO thin films.

    猜你喜歡
    時(shí)所光學(xué)薄膜
    復(fù)合土工薄膜在防滲中的應(yīng)用
    滑輪組的裝配
    Kappa運(yùn)動(dòng)搖搖杯
    中國品牌(2021年9期)2021-09-14 12:48:24
    光學(xué)常見考題逐個(gè)擊破
    β-Ga2O3薄膜的生長(zhǎng)與應(yīng)用
    光源與照明(2019年4期)2019-05-20 09:18:18
    一種不易起皮松散的柔軟型聚四氟乙烯薄膜安裝線
    電線電纜(2017年2期)2017-07-25 09:13:35
    CIGS薄膜太陽電池柔性化
    光學(xué)遙感壓縮成像技術(shù)
    Endress+Hauser 光學(xué)分析儀WA系列
    舉手之勞做環(huán)保之時(shí)令果蔬篇
    亚洲性久久影院| 亚洲国产日韩欧美精品在线观看| 在线观看午夜福利视频| 国产成年人精品一区二区| 亚洲中文字幕日韩| 99热这里只有是精品50| 国产精品一区www在线观看 | 不卡视频在线观看欧美| 婷婷丁香在线五月| 亚洲黑人精品在线| 日韩欧美三级三区| 22中文网久久字幕| 国产伦一二天堂av在线观看| 精品久久久久久成人av| 韩国av在线不卡| 99久久无色码亚洲精品果冻| 亚洲av美国av| 黄片wwwwww| 午夜免费成人在线视频| 国产免费一级a男人的天堂| 欧美激情国产日韩精品一区| 在线免费观看不下载黄p国产 | 国产久久久一区二区三区| 男插女下体视频免费在线播放| 久久久久久伊人网av| 欧美+亚洲+日韩+国产| 国产精品不卡视频一区二区| 亚洲男人的天堂狠狠| 在线免费十八禁| 午夜老司机福利剧场| 国产精品日韩av在线免费观看| 精品国产三级普通话版| 国产一区二区三区视频了| 99热这里只有是精品50| av在线老鸭窝| 欧美极品一区二区三区四区| 欧美成人一区二区免费高清观看| 国产精品一及| 午夜福利在线在线| 亚洲性久久影院| 九九爱精品视频在线观看| 99久久精品国产国产毛片| 色哟哟·www| 欧美日本亚洲视频在线播放| 又紧又爽又黄一区二区| 在线观看66精品国产| 网址你懂的国产日韩在线| 不卡视频在线观看欧美| 又黄又爽又免费观看的视频| 国产av一区在线观看免费| 嫩草影院入口| 日本免费a在线| 日韩强制内射视频| 一进一出好大好爽视频| 亚洲国产精品sss在线观看| 国产高清不卡午夜福利| 91狼人影院| 天堂网av新在线| 一卡2卡三卡四卡精品乱码亚洲| 久久久久性生活片| 男女视频在线观看网站免费| 听说在线观看完整版免费高清| 久久久久久国产a免费观看| 在线免费观看的www视频| 久久精品91蜜桃| 欧美人与善性xxx| 成人综合一区亚洲| 女的被弄到高潮叫床怎么办 | 色综合婷婷激情| 中文字幕人妻熟人妻熟丝袜美| 无人区码免费观看不卡| 欧美成人a在线观看| 91久久精品国产一区二区三区| 日韩精品有码人妻一区| 亚洲 国产 在线| 国语自产精品视频在线第100页| 麻豆一二三区av精品| 直男gayav资源| xxxwww97欧美| 日韩亚洲欧美综合| 色播亚洲综合网| 国产精品爽爽va在线观看网站| 他把我摸到了高潮在线观看| 亚洲精品在线观看二区| 亚洲成人免费电影在线观看| 婷婷亚洲欧美| 精品久久久久久久人妻蜜臀av| 亚洲av成人精品一区久久| 亚洲在线自拍视频| 免费观看精品视频网站| 看片在线看免费视频| 欧美日本视频| 国产在视频线在精品| 亚洲人成伊人成综合网2020| 成年版毛片免费区| 赤兔流量卡办理| 中文字幕人妻熟人妻熟丝袜美| 男人狂女人下面高潮的视频| 99热6这里只有精品| 一本久久中文字幕| 两个人视频免费观看高清| 欧美精品国产亚洲| 丰满人妻一区二区三区视频av| 九九久久精品国产亚洲av麻豆| 亚洲精品在线观看二区| 嫩草影视91久久| 亚洲精品在线观看二区| 精品人妻1区二区| 免费观看在线日韩| 成人高潮视频无遮挡免费网站| 99久久精品一区二区三区| 欧美国产日韩亚洲一区| 极品教师在线视频| 99热6这里只有精品| 好男人在线观看高清免费视频| 欧美黑人巨大hd| 校园人妻丝袜中文字幕| 日本免费a在线| 99riav亚洲国产免费| 男人和女人高潮做爰伦理| 精品免费久久久久久久清纯| 亚洲最大成人av| 少妇的逼好多水| 日韩欧美三级三区| 久久久成人免费电影| 亚洲成人中文字幕在线播放| 亚洲真实伦在线观看| 国产精品综合久久久久久久免费| 成人特级黄色片久久久久久久| 两性午夜刺激爽爽歪歪视频在线观看| 欧美高清成人免费视频www| 国产色婷婷99| 中文在线观看免费www的网站| 九九爱精品视频在线观看| 精品午夜福利视频在线观看一区| 日本黄色片子视频| 久久精品国产99精品国产亚洲性色| 热99re8久久精品国产| 欧美丝袜亚洲另类 | 99久久九九国产精品国产免费| 国产精品久久久久久久电影| 国产女主播在线喷水免费视频网站 | 欧美+日韩+精品| 成人高潮视频无遮挡免费网站| 亚洲色图av天堂| 白带黄色成豆腐渣| 国产乱人伦免费视频| 看十八女毛片水多多多| 欧美最新免费一区二区三区| av福利片在线观看| 欧美三级亚洲精品| 久久精品91蜜桃| 久久久久久九九精品二区国产| 亚洲中文字幕一区二区三区有码在线看| 小说图片视频综合网站| 日本黄大片高清| 波多野结衣高清无吗| 老熟妇仑乱视频hdxx| 999久久久精品免费观看国产| 又紧又爽又黄一区二区| 波野结衣二区三区在线| 伦理电影大哥的女人| 天天一区二区日本电影三级| 国产成人一区二区在线| 亚洲精华国产精华液的使用体验 | 日本 av在线| 一a级毛片在线观看| 日本 av在线| 精品一区二区免费观看| 99热网站在线观看| 日韩欧美一区二区三区在线观看| 精品国产三级普通话版| 免费av毛片视频| 最好的美女福利视频网| 五月伊人婷婷丁香| 亚洲综合色惰| 日韩强制内射视频| 97热精品久久久久久| 久久久国产成人免费| 欧美丝袜亚洲另类 | 国产毛片a区久久久久| 欧美日韩综合久久久久久 | 3wmmmm亚洲av在线观看| 国产成年人精品一区二区| 天堂√8在线中文| 色哟哟·www| 狠狠狠狠99中文字幕| 综合色av麻豆| 日韩强制内射视频| 99热网站在线观看| 高清日韩中文字幕在线| 亚洲精品在线观看二区| 此物有八面人人有两片| 国产精品av视频在线免费观看| 变态另类丝袜制服| 99国产精品一区二区蜜桃av| 日本 欧美在线| 亚洲黑人精品在线| a在线观看视频网站| 桃红色精品国产亚洲av| 1024手机看黄色片| 18禁黄网站禁片午夜丰满| 成年免费大片在线观看| 久久草成人影院| 在线播放国产精品三级| 老师上课跳d突然被开到最大视频| 老女人水多毛片| 日日摸夜夜添夜夜添小说| 亚洲午夜理论影院| 欧美+日韩+精品| 老熟妇乱子伦视频在线观看| 国产亚洲精品久久久久久毛片| 色在线成人网| 国产欧美日韩精品亚洲av| 欧美日韩乱码在线| 69av精品久久久久久| 欧美xxxx性猛交bbbb| 久久精品国产亚洲网站| 久久久久精品国产欧美久久久| 亚洲欧美日韩高清在线视频| 国产伦一二天堂av在线观看| 久久精品91蜜桃| 久久国产乱子免费精品| 亚洲精品国产成人久久av| 亚洲精品影视一区二区三区av| 免费观看的影片在线观看| 国产淫片久久久久久久久| 亚洲av电影不卡..在线观看| 国产伦精品一区二区三区四那| 国产精品亚洲美女久久久| 欧美日韩综合久久久久久 | 此物有八面人人有两片| 久久99热这里只有精品18| 日本精品一区二区三区蜜桃| 校园人妻丝袜中文字幕| 日本欧美国产在线视频| 亚洲欧美激情综合另类| 亚洲精品乱码久久久v下载方式| 免费一级毛片在线播放高清视频| 欧美人与善性xxx| 成人毛片a级毛片在线播放| 亚洲美女视频黄频| 国产精品免费一区二区三区在线| 国产亚洲91精品色在线| 制服丝袜大香蕉在线| 久久久久九九精品影院| 欧美xxxx性猛交bbbb| 亚洲avbb在线观看| 中文字幕久久专区| 91狼人影院| 日本黄色视频三级网站网址| 色在线成人网| 99热只有精品国产| 免费搜索国产男女视频| 欧美3d第一页| 成人精品一区二区免费| 欧美三级亚洲精品| 国产精品av视频在线免费观看| 国产精品自产拍在线观看55亚洲| 麻豆国产av国片精品| 1024手机看黄色片| 最新在线观看一区二区三区| 99热这里只有是精品50| 看十八女毛片水多多多| 亚洲成人精品中文字幕电影| 我的女老师完整版在线观看| 欧美日韩中文字幕国产精品一区二区三区| 亚洲精华国产精华精| 18禁黄网站禁片午夜丰满| 一级av片app| 乱码一卡2卡4卡精品| 18+在线观看网站| 亚洲精品一卡2卡三卡4卡5卡| 男人舔奶头视频| 国产精品,欧美在线| 精品久久久久久久久av| 99riav亚洲国产免费| 蜜桃亚洲精品一区二区三区| 一本精品99久久精品77| 亚洲精华国产精华液的使用体验 | 国产一区二区激情短视频| 亚洲aⅴ乱码一区二区在线播放| 国产淫片久久久久久久久| 欧美极品一区二区三区四区| 欧美潮喷喷水| .国产精品久久| 亚洲真实伦在线观看| 亚州av有码| 久久6这里有精品| 欧美xxxx性猛交bbbb| 又爽又黄a免费视频| 黄色配什么色好看| 亚洲人成网站在线播放欧美日韩| 欧美日本亚洲视频在线播放| 欧美黑人欧美精品刺激| 男插女下体视频免费在线播放| 国产真实伦视频高清在线观看 | 如何舔出高潮| 国产精品国产高清国产av| 久久久午夜欧美精品| 国产伦精品一区二区三区视频9| 亚洲精品国产成人久久av| 国产人妻一区二区三区在| 国产精品永久免费网站| 在线国产一区二区在线| 一个人看的www免费观看视频| 亚洲真实伦在线观看| 丰满人妻一区二区三区视频av| 夜夜爽天天搞| 夜夜夜夜夜久久久久| 国产成人一区二区在线| 免费观看在线日韩| 欧美bdsm另类| 一区二区三区四区激情视频 | 亚洲专区国产一区二区| 久久精品夜夜夜夜夜久久蜜豆| 免费大片18禁| 国产精华一区二区三区| 九九爱精品视频在线观看| 国产精品亚洲美女久久久| 欧美一区二区精品小视频在线| 日日撸夜夜添| 丝袜美腿在线中文| 国产在线精品亚洲第一网站| 日韩中文字幕欧美一区二区| 色在线成人网| 99在线人妻在线中文字幕| 亚洲精品久久国产高清桃花| 精品午夜福利视频在线观看一区| 国产精品人妻久久久久久| 亚洲中文字幕一区二区三区有码在线看| 最新中文字幕久久久久| 日韩欧美免费精品| 少妇人妻精品综合一区二区 | 亚洲色图av天堂| 亚洲精品成人久久久久久| 国产精品女同一区二区软件 | 欧美+日韩+精品| 99久久久亚洲精品蜜臀av| 成人特级av手机在线观看| x7x7x7水蜜桃| 特级一级黄色大片| 欧美bdsm另类| 性色avwww在线观看| 国产又黄又爽又无遮挡在线| 中文字幕av成人在线电影| 亚洲精品色激情综合| 欧美xxxx黑人xx丫x性爽| 极品教师在线视频| 国产乱人伦免费视频| 国产精品免费一区二区三区在线| 久久九九热精品免费| 久久久久久久久久久丰满 | 一区二区三区高清视频在线| 成年女人永久免费观看视频| 国产亚洲av嫩草精品影院| 欧美日韩亚洲国产一区二区在线观看| 伊人久久精品亚洲午夜| 搡老岳熟女国产| 国产伦人伦偷精品视频| 韩国av在线不卡| 国产伦在线观看视频一区| 亚洲av中文av极速乱 | 精品日产1卡2卡| 婷婷精品国产亚洲av| 我的女老师完整版在线观看| 亚洲av熟女| 亚洲av电影不卡..在线观看| 国产精品乱码一区二三区的特点| 国产午夜精品久久久久久一区二区三区 | 国产视频内射| 91在线观看av| 免费看a级黄色片| 国产精品精品国产色婷婷| 在线看三级毛片| 搡老熟女国产l中国老女人| 亚洲真实伦在线观看| 18禁在线播放成人免费| 国产日本99.免费观看| 国产亚洲精品综合一区在线观看| 亚洲精品在线观看二区| 国产精品精品国产色婷婷| 成年免费大片在线观看| 亚洲,欧美,日韩| 91av网一区二区| 久久6这里有精品| 亚洲国产精品久久男人天堂| 国产乱人伦免费视频| 国产免费av片在线观看野外av| 一区二区三区免费毛片| 老师上课跳d突然被开到最大视频| 日本成人三级电影网站| 精品乱码久久久久久99久播| 男人的好看免费观看在线视频| 久久久久久久亚洲中文字幕| 麻豆久久精品国产亚洲av| 有码 亚洲区| 国内精品久久久久久久电影| 成人精品一区二区免费| 国产乱人视频| 麻豆国产97在线/欧美| 99热这里只有是精品在线观看| 亚洲av五月六月丁香网| 国产av不卡久久| 成人鲁丝片一二三区免费| 三级男女做爰猛烈吃奶摸视频| 久久精品影院6| 国产精品伦人一区二区| 日韩中文字幕欧美一区二区| 亚洲精品国产成人久久av| 99热这里只有是精品在线观看| 亚洲欧美日韩东京热| 91av网一区二区| 俺也久久电影网| 亚洲精华国产精华液的使用体验 | 国产高清视频在线播放一区| 久久久久久国产a免费观看| 两人在一起打扑克的视频| 欧美日韩瑟瑟在线播放| 精品午夜福利在线看| 两人在一起打扑克的视频| 三级男女做爰猛烈吃奶摸视频| 天堂√8在线中文| 国产日本99.免费观看| 亚洲最大成人中文| 99久久中文字幕三级久久日本| 禁无遮挡网站| 日韩欧美在线乱码| 国产不卡一卡二| 国产亚洲精品久久久com| 日日夜夜操网爽| 搡老岳熟女国产| 深爱激情五月婷婷| a在线观看视频网站| 成人美女网站在线观看视频| 亚洲欧美日韩东京热| 亚洲精品成人久久久久久| 最后的刺客免费高清国语| 国内精品久久久久精免费| 国产高清视频在线播放一区| av在线天堂中文字幕| 免费黄网站久久成人精品| 日本-黄色视频高清免费观看| 国产精品日韩av在线免费观看| 亚洲一区高清亚洲精品| 一个人看的www免费观看视频| 欧美精品国产亚洲| 非洲黑人性xxxx精品又粗又长| 熟妇人妻久久中文字幕3abv| 亚洲综合色惰| 性欧美人与动物交配| 又粗又爽又猛毛片免费看| 老熟妇仑乱视频hdxx| 久久亚洲精品不卡| 别揉我奶头~嗯~啊~动态视频| 欧美人与善性xxx| 丰满人妻一区二区三区视频av| 成人av在线播放网站| h日本视频在线播放| 色哟哟·www| 免费黄网站久久成人精品| 一区二区三区高清视频在线| 国产黄色小视频在线观看| 欧美最黄视频在线播放免费| 欧美bdsm另类| 能在线免费观看的黄片| 免费看光身美女| 少妇的逼好多水| 校园春色视频在线观看| 国内少妇人妻偷人精品xxx网站| av视频在线观看入口| 精品国内亚洲2022精品成人| 精品人妻1区二区| 欧美成人一区二区免费高清观看| 国产伦精品一区二区三区四那| 3wmmmm亚洲av在线观看| 精品欧美国产一区二区三| 成人永久免费在线观看视频| 我的女老师完整版在线观看| 亚洲人成伊人成综合网2020| 国产精品1区2区在线观看.| 久久精品综合一区二区三区| 99热这里只有精品一区| 国产精品综合久久久久久久免费| 日日干狠狠操夜夜爽| 成人综合一区亚洲| 欧美日韩精品成人综合77777| 久9热在线精品视频| 欧美精品啪啪一区二区三区| 天堂√8在线中文| 女的被弄到高潮叫床怎么办 | 少妇裸体淫交视频免费看高清| 国产aⅴ精品一区二区三区波| 国产男靠女视频免费网站| a在线观看视频网站| 国产精品99久久久久久久久| 深夜精品福利| 久久草成人影院| 12—13女人毛片做爰片一| 99国产精品一区二区蜜桃av| 国产伦精品一区二区三区四那| 草草在线视频免费看| 非洲黑人性xxxx精品又粗又长| 欧美日韩综合久久久久久 | 精品人妻熟女av久视频| 国语自产精品视频在线第100页| a级毛片免费高清观看在线播放| 在线播放国产精品三级| 最好的美女福利视频网| 午夜精品在线福利| 伦理电影大哥的女人| 国产精品爽爽va在线观看网站| 中文字幕人妻熟人妻熟丝袜美| 无遮挡黄片免费观看| 国产淫片久久久久久久久| 99久久九九国产精品国产免费| 琪琪午夜伦伦电影理论片6080| 99久久成人亚洲精品观看| 亚洲成人精品中文字幕电影| 99热6这里只有精品| 亚洲电影在线观看av| 欧美黑人巨大hd| 老司机深夜福利视频在线观看| 国产一区二区亚洲精品在线观看| 国产又黄又爽又无遮挡在线| 黄片wwwwww| 桃色一区二区三区在线观看| 12—13女人毛片做爰片一| 日韩高清综合在线| 免费无遮挡裸体视频| 亚洲av一区综合| 中文资源天堂在线| 国产精品三级大全| 国产综合懂色| 91麻豆精品激情在线观看国产| 亚洲av电影不卡..在线观看| 亚洲成人精品中文字幕电影| 少妇人妻精品综合一区二区 | 国产主播在线观看一区二区| 国产视频内射| 99久久久亚洲精品蜜臀av| 欧美成人一区二区免费高清观看| 久久久久久久久久成人| 91久久精品国产一区二区三区| 国产探花在线观看一区二区| 99久久中文字幕三级久久日本| 亚洲精品乱码久久久v下载方式| 午夜福利18| 一级黄片播放器| 成人av一区二区三区在线看| 99久久精品国产国产毛片| 欧美区成人在线视频| 免费人成视频x8x8入口观看| 搞女人的毛片| 深爱激情五月婷婷| 中文字幕高清在线视频| 国国产精品蜜臀av免费| 波多野结衣巨乳人妻| 91麻豆精品激情在线观看国产| 亚洲精品乱码久久久v下载方式| 国产真实伦视频高清在线观看 | 中文亚洲av片在线观看爽| 亚洲aⅴ乱码一区二区在线播放| 伦精品一区二区三区| 噜噜噜噜噜久久久久久91| 成人欧美大片| 波多野结衣高清作品| 久久人妻av系列| 色综合亚洲欧美另类图片| 中文字幕免费在线视频6| 美女免费视频网站| 免费看av在线观看网站| 午夜免费成人在线视频| 一进一出抽搐动态| 12—13女人毛片做爰片一| 亚洲四区av| 亚洲第一区二区三区不卡| 亚洲va在线va天堂va国产| 欧美日韩综合久久久久久 | 欧美丝袜亚洲另类 | 亚洲四区av| 一区二区三区激情视频| 18禁裸乳无遮挡免费网站照片| av天堂中文字幕网| 色精品久久人妻99蜜桃| 婷婷精品国产亚洲av| 男女视频在线观看网站免费| 又黄又爽又免费观看的视频| 日日干狠狠操夜夜爽| 两性午夜刺激爽爽歪歪视频在线观看| 偷拍熟女少妇极品色| 日日摸夜夜添夜夜添av毛片 | 精品久久久噜噜| 波多野结衣高清作品| 啦啦啦观看免费观看视频高清| 亚洲国产欧洲综合997久久,| 成人美女网站在线观看视频| 精品午夜福利在线看| 久久久精品大字幕| 国产亚洲91精品色在线| 欧美最黄视频在线播放免费| 久久久精品欧美日韩精品| 内射极品少妇av片p| 欧美xxxx黑人xx丫x性爽| 亚洲成人久久性| 亚洲人成伊人成综合网2020| 精品久久久久久久久亚洲 | 欧美日本亚洲视频在线播放| 久久99热6这里只有精品| 亚洲乱码一区二区免费版| 一级av片app| 一a级毛片在线观看| 色尼玛亚洲综合影院| 国产91精品成人一区二区三区| 国产在线精品亚洲第一网站|