We report on a new photodetector fabricated using carbon nanostructures grown on a silicon substrate. This device exhibits low noise, a good conversion efficiency of photons into electrical current and a good signal linearity in a wide range of radiation wavelengths ranging from ultraviolet to infrared at room temperature. The maximum quantum efficiency of 37% at 880 nm has been measured without signal amplification. Such innovative devices can be easily produced on large scales by Chemical Vapour Deposition (CVD) through a relatively inexpensive chemical process, which allows large sensitive areas from a few mm2 up to hundreds of cm2 to be covered.