TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The solar cell comprises a glass cover. The energy source is electrical heating, UV irradiation, infra red irradiation, microwave irradiation, X-ray irradiation, electron beam, radio frequency or plasma (preferred).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The reactant gas is a suitable nitrogen- or oxygen-containing gas, preferably nitrogen, ammonia, nitrogen trichloride, nitric oxide, nitrogen dioxide, oxygen, ozone, carbon monoxide and/or carbon dioxide.    TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The method further comprises mixing the gaseous precursor with a reactant gas prior to the reacting step. The antireflective coating is prepared: from the pyrolysis product of polydimethylsilane (PDMS), polycarbomethylsilane (PCMS), triphenylsilane and/or nonamethyltrisilazane, preferably PDMS and/or PCMS; by energy induced chemical vapor deposition of a gaseous precursor obtained by the pyrolysis of PDMS, PCMS, triphenylsilane or nonamethyltrisilazane, preferably PDMS or PCMS; by plasma-enhanced chemical vapor deposition of a gaseous precursor obtained by the pyrolysis of PDMS, PCMS, triphenylsilane or nonamethyltrisilazane, preferably PDMS or PCMS; by spin-coating a liquid phase of PDMS, PCMS, triphenylsilane and/or nonamethyltrisilazane, preferably PDMS and/or PCMS; or by electrostatic deposition of a gaseous precursor obtained by the thermal decomposition of PDMS, PCMS, triphenylsilane and/or nonamethyltrisilazane, preferably PDMS and/or PCMS. The organosilanes and/or organopolysilanes are gaseous, and the deposition step is carried out by reacting the gases using an energy source. The film is formed on the substrate by plasma enhanced chemical vapor deposition (PECVD), radio frequency plasma enhanced chemical vapor deposition (RF-PECVD), electron-cyclotron-resonance plasma-enhanced chemical-vapor deposition (ECR-PECVD), inductively coupled plasma-enhanced chemical-vapor deposition (ICP-ECVD) and/or plasma beam source plasma enhanced chemical vapor deposition (PBS-PECVD). The deposition step is: carried out a pressure of greater than 100 torr; carried out by spin coating a liquid phase of the solid organosilane source, such as PDMS or PCMS, followed by a thermal anneal; and carried out by electrostatic deposition. The antireflective coating has a graded refractive index along a thickness, where the coating has, at a selected thickness, a refractive index of 2.3-2.7 and an extinction coefficient of less than 0.01 at a wavelength of 630 nm, and a composition that is the same as the composition of the film. Preferred Components: The amorphous silicon carbide-based film is an amorphous silicon carbide, amorphous silicon carbonitride, amorphous silicon oxycarbonitride or amorphous silicon oxycarbide film. The effective refractive index (n) is 2.3-2.4. The film has many layers and the refractive index of each layer varies from 1.5 to 2.7. The film has a graded refractive index along a thickness. The extinction coefficient (k) is less than 0.001. The coating does not absorb more than 1% of incident light in the wavelength range of 300-1200 nm. The film has a reflectivity of less than 1% at a wavelength of 630 nm. The film, deposited on a silicon substrate and covered by glass, has an average light reflectivity at wavelengths of 400-1200 nm of less than or equal to 7%. The refractive index is stable after annealing the antireflective coating at 700-850 degrees C. The extinction coefficient remains stable or decreases after annealing the antireflective coating at 700-850 degrees C. The antireflective coating has a thickness of 50-160 nm. The variation of the thickness is less than 1% after firing at 700-900 (preferably 850-875) degrees C for 1-15 (preferably 3-5) seconds. The antireflective coating has a hardness of 15-25 (preferably 18-22) Gpa. The residual mechanical stress in the coating is less than or equal to 150 MPa. The film has: a hydrogen concentration, in atomic percent, of 10-40%, preferably 10-15%; a silicon concentration, in atomic percent, of 30-70%, preferably 50%; a carbon concentration, in atomic percent, of 3-60%, preferably 25-35%; a nitrogen concentration, in atomic percent, of 0-50%, e.g. 10-45%, 20-40%, or 25-35%; and an oxygen concentration, in atomic percent, of 0-50%, preferably 22-28%. The solid organosilane source is polydimethylsilane, polycarbomethylsilane, triphenylsilane and/or nonamethyltrisilazane. The solid organosilane source comprises a synthetic ratio of isotopes. EXAMPLE - Polydimethylsilane (400 g) was placed in stainless steel vessel (2 l). Once sealed, the gas within the vessel was purged and replaced with argon. The vessel was then heated at a rate of 150 degrees C per hour to 422 degrees C and then maintained at this temperature for three hours. While maintaining the temperature substantially constant, gaseous products obtained were released from the vessel at 805 psi, thus reducing the pressure. Between releases of the gaseous products, the pressure within the vessel was allowed to increase as additional gaseous products were produced from the polydimethylsilane. The pressure in the vessel was maintained between 600 degrees C and 900 psi. The obtain gas flow was then fed to the plasma enhanced chemical vapor deposition system. The total flow of gas was adjusted to keep a pressure of 0.900 torr inside the deposition chamber. The radio frequency power was 200 watts. The duration of deposition was 9 minutes and the temperature of the substrate was 400 degrees C. After removal from the deposition chamber, the silicon wafer was found to be coated with an amorphous silicon carbide film having a refractive index of 2.35, an extinction coefficient value of approximately 0.004 at 630 nm, and a film thickness of 80 nm.