Abstract: Method is provided for reducing the sensitivity of energetic materials (explosives, propellants and the like) to detonation induced by mechanical shock or by application of pronounced heat, e.g. by a laser beam. Examples of such energetic materials are fluorine azide and chlorine azide which are model HEDM propellants which are prone to accidental detonation in the solid state. The polycrystalline forms of such solids are sensitive to and readily detonated by, mechanical shock and pulsed laser photolysis. The method of the invention serves to desensitize such energetic materials by forming them as amorphous (disordered) solids by vapor deposition thereof onto a relatively cold substrate, which amorphous form desensitizes them relative to more conventional polycrystalline forms of these energetic materials though both contain about the same amount of chemical energy.