The structural, optical, and electrical properties of Al-doped ZnO (ZnO:Al) thin films deposited by atomic layer deposition (ALD) with a modified precursor pulse sequence were investigated to evaluate the electromagnetic interference shielding effectiveness (EMI-SE). A Zn-Al-O precursor exposure sequence was used in a modified ALD procedure to result in better distribution of Al3+ ions in the ZnO matrix with the aim of reducing the formation of complete nano-laminated structures that may form in the typical alternating ZnO and Al2O3 deposition procedure. The ALD dopant concentration of the ZnO: Al films was varied by adjusting the dopant deposition intervals of the ZnO:Zn-Al-O precursor pulse cycle ratios among 24:1, 19:1, 14:1, and 9:1. The lowest obtained resistivity and average transmittance in the visible region (380-780 nm) were 5.876 x 10(-4) Omega cm (carrier concentration of 6.02 x 10(20) cm(-3) and Hall mobility of 17.65 cm(2)/V s) and 85.93% in the 131 nm thick ZnO: Al(19: 1) film, respectively. The average value of the EMI-SE in the range of 30 MHz to 1.5 GHz increased from 1.1 dB for the 121 nm thick undoped ZnO film to 6.5 dB for the 131 nm thick ZnO: Al(19: 1) film. (C) 2012 Elsevier B. V. All rights reserved.