A new technique to passivate silicon surfaces using SnO₂ films, produced by decomposing organic films of the octadecylamine- stannate complex, deposited by the Langmuir–Blodgett (L–B) technique, has been attempted to fabricate silicon surface barrier detectors. This method of passivation is relatively simpler and can be carried out at a much lower temperature as compared to the usual passivation method of the silicon surface by growing the SiO₂ layer on it. Also, the passivating layer of SnO₂ produced in this new method has a good shelf-life. The detectors fabricated with a passivating layer of SnO₂ were subsequently tested for I –V, alpha spectrum and long-term performance.