In this work, ZnO ,N-doped ZnO(NZO) , Al-doped ZnO(AZO) and Al,N-doped ZnO(ANZO) thin films were prepared by the sol-gel spin-coating method based on zinc acetate dihydrate(CH 3 COO) 2 Zn·2H 2 O, Aluminium acetate (C 4 H 7 AlO 5 ), Ammonium acetate(CH 3 COONH 4 ), absolute ethanol (C 2 H 5 OH) and diethanolamine ((HOCH 2 CH 2 ) 2 NH, DEA). All films were spin-coated on borosilicate substate for several coating repetition followed by annealing process at 550 O C for 4 hr in air. The structural properties and surface morphologies of films were characterized by X -ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FE-SEM). The optical properties of the films were interpreted from their transmission spectra using UV-VIS spectrophotometer.The XRD patterns of NZO with various N-doping content 5% and 10% are illustrated in Fig.1 and The XRD patterns of AZO with various Al-doping content 5% and 10% are shown in Fig. 2. The distinct diffraction peaks positioned at 2ș=31.8°, 34.5°, 36.2° , 47.5° and 56.7° are assigned to (100), (002), (101), (102) and (110) orientation planes of ZnO with hexagonal wurtzite structure, respectively. As seen in XRD patterns, both Al-doped and N-doped ZnO films exhibit three diffracted peaks suggesting that asprepared films have single-phase polycrystalline structure with no preferable orientation. This characteristic of XRD pattern is attributed to the typical formation of ZnO prepared by sol-gel route [1]. The position of all prominent peaks shows insignificant change with either N and Al doping content indicating good stability of hexagonal crystalline structure of ZnO. In addition, the significant deterioration in crystallinity of the films was observed in AZnO films. Fig. 3(a), (b) and (c) illustrate surface morphology of undoped film, 5%N-doped film, and 10%Ndoped film, respectively. It is clearly observed that all films have smooth surface comprising uniform grain size. As the N-doping concentration increases, the crystallinity of the film significantly improves with decreasing grain size. Fig. 4(a), (b) and (c) illustrate surface morphology of undoped film, 5%Aldoped film, and 10%Al-doped film, respectively. It is clearly observed that the grain size of the film drastically decreases as Al-doping content increases. The SEM results are in good agreement to results interpreted from XRD patterns.As shown in Fig. 5, transmission spectra of as-prepared thin films possess prominent absorption edge in visible range, suggesting good quality of films obtained by spin coating. All films are highly transparent in the visible region with more than 85-95% transparency within visible region of 400-800nm. As Al-doping concentration increases, the transmission spectra exhibit the obvious blue shift of absorption edge to lower wavelength implying the higher shift of optical band gap of the film with increasing Al-doping concentration. The noticeable blue shift are also observed in the N-doped films. The shift in energy gap of Al-doped and N-doped ZnO films may attribute to the alloy...