Arrays of surface-guided nanowires with controlled orientations and morphology are promising as building blocks for various applications and for systematic research. We report the horizontal and aligned growth of CsPbBr3 nanowires with different diameters and uniform crystallographic orientation. We observe and disscuse their waveguiding behavior and diameter-dependent photoluminescence emission well beyond the quantum confinement regime. Flat and faceted sapphire surfaces are used to form arrays with 6-fold and 2-fold symmetries, respectively, that are easily integrated into multiple devices, displaying p-type behavior and photoconductivity. Photodetectors based on those nanowires exhibit the fastest rise and decay times for any CsPbBr3-based photodetectors reported so far.