A new synthesis route for the formation of HTSC films of on a viable substrate e.g. MgO by spray pyrolysis has been found through the addition of in appropriate solution mixture. The works as a rate enhancer catalyst which on dissociation during the film processing at supplies active oxygen necessary for the synthesis of HTSC . The transition for the present film was found to be K for an Ag concentration of 0.10. The observed is comparable with values of film prepared through other routes. In addition through dissociation also provides Ag, which enters the grain boundaries, leading to their passivation. The silver also appears to act as a surfactant, resulting in an enlargement of grain size (e.g. 1.0 to 5.0 m for Ag concentrations of 0.05 and 0.10 respectively). Both these effects ensuing from Ag lead to an enhancement of critical current density, . The optimum of at 16 K has been found for the Ag concentration of 0.10. Thus in the present synthesis of films, both the supply of oxygen required for development of HTSC phase and enhancement of critical current density based on grain boundary passivation and enlargement of grain sizes (decrease of grain boundary density) have been obtained by the singular process of addition of an appropriate concentration of .