金属Al背电极二维AZO光栅的制备和陷光特性

Preparation and Light Trapping Properties of Two-dimensional AZO Gratings on Metal Aluminum Back Contact

研究了背电极金属Al膜上二维ZnO:Al光栅的制备及其反射光谱特性.在厚度为300 nm的Al膜上溅射80 nm ZnO:Al薄膜,旋涂AZ5206光刻胶,用波长为325 nm的激光进行光刻制作光栅掩模.采用溶脱-剥离法在Al衬底上制备周期(624~1250 nm)和槽深(100~300 nm)可独立调控的ZnO:Al二维光栅.表面形貌采用原子力显微镜和扫描电镜观察,反射光谱用带积分球的分光光度计测试,双向反射分布函数用散射仪测量.结果表明,300 nm Al膜上织构二维ZnO:Al光栅背电极结构,当光栅槽深为228 nm,周期从624 nm增加到986 nm时,背电极总反射率、漫反射率以及雾度均随光栅周期增大而显著增加,而当周期从986 nm增加到1250 nm时,总反射率、漫反射率以及雾度略有增加.双向反射分布函数测试结果进一步证实了上述实验结果,即随着周期增大,漫反射峰值越大,衍射峰个数也增多.提示背反电极上槽深为228 nm、周期为986 nm的二维ZnO:Al光栅具有较好的散射效果,其中漫反射占总反射的百分比为45%.

To discuss the preparation and reflective spectral properties of two-dimensional aluminum-doped zinc oxide(ZnO:Al)gratings on back contact mental Al,a thickness of 80 nm ZnO:Al thin film was deposited on 300 nm Al substrate,then a layer of AZ5206 photo-resist was spin coated on ZnO:Al thin film.Mask pattern was acquired with 325 nm laser holographic lithography.Using lift off technology,two-dimensional ZnO:Al gratings with 624~1250 nm periods and 100~300 nm heights on Al substrate were acquired.Grating periods and heights could be regulated independently.Surface morphologies were observed by atomic force microscopy and scanning electron microscopy,reflection spectrum was tested using spectrophotometer with integrating sphere,bidirectional reflectance distribution function was measured by scattering instrument.Results showed that total reflectivity,diffuse reflectivity and haze of those gratings with 228 nm heights all increased obviously as periods increasing from 624 nm to 986 nm.As periods increasing from 986 nm to 1250 nm,the increment of total,diffuse reflectivity and haze were only small.The tested results of bidirectional reflectance distribution functions further confirmed the above conclusions,namely more large periods,more large diffuse reflectivity peak value,and more peak position numbers.It was concluded that back contact ZnO:Al grating with 986 nm period and 228 nm height had excellent scattering effects,such as the percentage of diffuse reflectivity to total reflectivity was up to 45%.