Technique for depositing coatings by pyrolysis/decomposition of precursor gas or gases

A nozzle for distributing at leas tone current of precursor gases onto a surface of a moving glass substrate of the float glass ribbon type, the precursor gases being adapted for forming, on contact with the substrate, a coating by pyrolysis/decomposition reaction, comprising:

• a nozzle body;
• principal gas feed means for feeding a principal gas to said nozzle body, said principal gas comprising the at least one current of the precursor gases;
• and
• auxiliary gas feed means independent of said principal gas feed means for feeding an auxiliary gas to said nozzle body in the proximity of a principal gas in said nozzle body for locally modifying the chemical composition of the principal gas, said auxiliary gas comprising at least one of said precursor gases.