The aim of this project is to obtain Ge_xSn_1-x by magnetron sputtering (MS) for field effect (FE) enhanced photo-sensing in extended near-infrared (NIR) range 1-3um. Sensitive detection of infrared (IR) light, especially in the mid- and far-infrared ranges, is extremely desirable in many important fields such as biology, astronomy, and medical science. The present IR photodetector market is dominated by III-V (InGaAs) alloys and chalcogenides (PbS, PbSe), materials of high toxicity and incompatible with silicon technology for integrated photonics. Therefore, it is important to develop new material technology based on ecologic materials as those of IV group elements, compatible with silicon technology for monolithic photonic integration. The advantage of alloying a semiconductor Ge with a semimetal Sn is the reduction of the bandgap, extending the NIR sensitivity of Ge, but also in obtaining a transition to direct bandgap IV-group semiconductors with higher optoelectronic properties. The project proposes the fabrication of Ge_xSn_1-x/oxide/Si-substrate structures. Sn concentration, layer thickness, deposition temperature, and post-annealing parameters will be varied for optimization of Ge_xSn_1-x films. Two type of structures will be grown by MS, nanostructured by rapid thermal annealing and characterized from point of view of structural, electrical and optical properties. The two types of structures refer to alternatives of using as gate oxide either thermally grown SiO₂ or HfO₂ deposited by MS. For obtaining a high spectral photoresponse, the Si substrate as a gate electrode will be employed. The unintentional doping due to local disorder (vacancies) in GeSn layers with negative consequences on photoconductivity properties is compensated by charges injected by FE, controlling the carrier density without creation of additional structural defects, changing the photo-carriers recombination and thus, improving the photoconduction properties of GeSn.