We report here the structural, FTIR, optical and dielectric properties of Zn1-xAlxO with x =
00.00 < x < 0.20)). The wurtzite structure is conformed to all samples and the lattice constants,crystallite diameter, porosity and average crystalline size are generally decreased. The residual stress is compressive for pure samples, but it is changed to tensile for the doped samples. Interestingly, Debye temperature and elastic modulus are increased as x increases to 0.10, followed by a decrease at x = 0.20. Two different energy gaps Egh and Egl are apparent for each sample, corresponding of two transition absorption peaks. Interestingly, the ΔE = (Egh – Egl) ~0.60 for all samples. Further, the residual dielectric constant is decreased by increasing x to 0.10,followed by a sharp increase at x = 0.20 while the opposite behavior for (N/m*). The dielectric constant ε′ is slightly increased as x increases to 0.025, followed by a sharp increase as x increases to 0.20, as well as the ac conductivity σ/. The conduction is electronic for x < 0.025 samples, but it is changed to hole with an increase of x to 0.20. The binding energy Wm was decreased as x increases to 0.20, but there is no exact trend against x for the behaviors of minimum hopping distance Rmin and density of localized states N. In addition, the density of states at Fermi level N (EF) has an optimum value at 195 KHz for all samples. The F-factor for solar cell design is increased as x increases to 0.10, but it is almost constant at x = 0.20. The Cole-Cole plot is a straight line for x = 0.00, a semicircle arc for x = 0.025 and a complete semicircle for x > 0.05. The impedance resistance of grain Z\(g) and grain boundaries Z\(gb) are gradually decreased by increasing x to 0.20. These outcomes indicate that the addition of Al to ZnO shifts the mechanical, optical, and dielectric medium to higher values, which is strongly recommended for the design of optoelectronic and solar cell instruments.