K掺杂量对K-N共掺ZnO薄膜光学性能的影响

Effect of K-doped on optical properties of K-N co-doped ZnO thin films

利用超声喷雾热解法在石英玻璃衬底上制备不同K掺杂量的K-N共掺ZnO薄膜.通过X射线衍射仪(XRD)、扫描电子显微镜(SEM)、光致发光谱(PL谱)和紫外-可见分光光度计对K-N共掺ZnO薄膜的晶体结构、表面形貌及光学性能进行表征.结果表明:K-N共掺ZnO薄膜为六方纤锌矿结构并沿(002)方向择优生长;随着K掺杂量的增加,薄膜紫外发射峰的强度先升高后降低,并且吸收边出现轻微蓝移,禁带宽度增大;K-N共掺ZnO薄膜的透过率随K的掺杂量的增加先升高后降低,在65%～70%之间浮动.当K掺杂原子比为0.025时,所制备的薄膜具有高度的c轴择优取向,其薄膜表面均匀、光滑平整,具有较好的结晶度和光学性能.

K-N co-doped ZnO thin films were prepared on quartz glass substrates by ultrasonic spray pyrolysis method with different K contents.The structures,surface morphologies and optical properties of K-N co-doped ZnO films were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),photoluminescence(PL)and UV-Vis spectrophotometer.The results show that K-N co-doped ZnO thin films have hexagonal wurtzite ZnO structures with a preferred orientation of the crystallites along(002)direction.In addition,the intensity of UV emission peak firstly increases and then decreases as K doping concentration increasing,and the transmittance cut-off wavelength exhibited a slight blue shift,which increases the band gap of the films.With the increase of K doping concentration,the transmittance of K-N co-doped ZnO film increases initially and decreases afterwards between65%and70%.When the atomic ratio of K doped is0.025,the prepared films own the better c-axis preferential orientation,the more uniform and smooth surface,the better crystalline quality and optical properties.