The application of hydrogenated amorphous silicon (a–Si:H) to optoelectronic devices are now well established as a viable low cost technology and is presently receiving much interest. Taking advantage of the properties of a–Si:H based devices, single and dual axis large area (up to 80×80 mm2) thin film position sensitive detectors (TFPSD) based on a–Si:Hp–i–ndiodes have been developed, produced by plasma enhanced chemical vapor deposition. In this study, the main optoelectronic properties presented by the TFPSD as well as their behavior under operation conditions, concerning its linearity and signal to noise ratio, are reported. ©1994 American Institute of Physics.