The self-catalyzed growth of InP nanowires on an aerographite substrate is demonstrated in this study by using high growth rate hydride vapor-phase epitaxy technology. Nanowires with aspect ratios higher than 200 and diameters of 0.2–2 μm were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive x-ray analysis, Raman spectroscopy, and photoelectrical characterization. The nanowires were found to be of constant diameter over their length, except for a well-faceted hexagonal tapered end. The novel growth process results in formation of self-catalyzed nanowires compatible with integrated circuit technology. Single-wire InP photodetectors with predominant sensitivity in the infrared spectral range have been prepared and characterized. Impact statement: Semiconductor nanowires gain wider application in light and gas sensors, memory and memristive devices. In this article, we describe a fast and rather simple approach of fabricating catalyst-free InP nanowires with aspect ratio of 200. Important benefits of this method are stoichiometric chemical composition and freestanding arrangement of wires on the aerographite substrate. We demonstrate the development of a robust IR single-nanowire sensor stable at 20–300 K both in the air and vacuum atmosphere, with I _ph/I _dark ratio in the range 4–1.7. Graphical abstract: [Figure not available: see fulltext.].