Amorphous and microcrystalline silicon thin-films are widely used in microelectronics and more specifically in solar cell industry. However vacuum deposition technologies are difficult to scale up to large area. Inkjet printing is a promising candidate and thus the functional properties recovering of printed silicon thin films study is a key issue. Special care is given to silicon ink formulation allowing proper deposition. Inks need to fill requirements in terms of surface tension, viscosity and stability in order to control the thin-film quality. The process requirements imply care of thermal budget. Thus a study of various sintering processes under vacuum and inert atmosphere is presented. Convective, Rapid Thermal and microwave annealing are compared. Electrical, optical and morphological effects of sintering and coalescence on molybdenum electrode and oxidized silicon substrates are presented. The nanoparticles size and surface chemistry as well as the heating method clearly impact the required temperature and time of sintering process. It is thus shown how functional layers can be obtained from silicon nanoparticles dispersion. Microwave annealing, diminishing sintering time and temperature, is clearly a promising candidate to allow a low treatment temperature, thus compatible with glass or other "low temperature" substrate. Mastering deposition of solution processed silicon with controlled physical properties opens the way to third generation solar cells development.