TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: Substrate is selected from glass and silicon wafer. Bi-layers are selected from antireflection coating (AR1) having 1st layer formed from titania sol and 2nd (top) layer formed from composite sol of SiO2-MPTS over titania layer, antireflection coating (AR2) having 1st layer formed from zirconia sol and 2nd (top) layer formed from composite sol of SiO2-MPTS over zirconia layer, antireflection coating (AR3) having 1st layer formed from titania-containing solution and 2nd (top) layer formed from composite sol of SiO2-ZrO2 over titania layer, antireflection coating (AR4) having 1st layer formed from zirconia sol and 2nd (top) layer formed from composite sol of SiO2-ZrO2 over zirconia layer, antireflection coating (AR5) having 1st layer formed from titania sol and 2nd (top) layer formed from composite sol of SiO2-TiO2 over titania layer, and antireflection coating (AR6) having 1st layer formed from zirconia sol and 2nd (top) layer formed from composite sol of SiO2-TiO2 over zirconia layer. Preferred Processes: Coating of both the layers is carried out by dip coating process in which dip tank and cantilevered arm of dip coating machine are placed in coating room having controlled humidity of 35-45% and temperature maintained at 20-25 degrees C, ensuring deposition of transparent defect-free coating layers. Withdrawal speeds of 2-3 mm/s and 0.5-1.5 mm/s are maintained during deposition of 1st coating layer and 2nd (top) coating layer, respectively, while hold time during dipping is maintained at 30 s in case of both coatings. The 1st layer of AR1, AR3, and AR5 bi-layer systems is prepared by mixing various constituents in ratio titanium isopropoxide (Ti(OiPr)): isopropanol (IPA): isopropoxy ethanol (IPETOH) of 4.2 : 82.2: 13.6 (wt.%). The 1st layer of AR2, AR4, and AR6 bi-layer systems is prepared by mixing various constituents in ratio zirconium propoxide (Zr-pro): IPA: 2-isopropoxy ethanol (2-IPETOH) of 7: 79.8: 13.2 (wt.%). Major portion of silica precursor containing sol mixture utilized for preparation of 2nd (top) layer for AR1 and AR2 systems is prepared by mixing various constituents in ratio tetra ethyl orthosilicate (TEOS): IPA: HCI : H2O : MPTS of 20.35 : 69.41 : 0.17 : 9.79: 0.28 (wt.%). Composite sol of SiO2-ZrO2 utilized for preparation of 2nd (top) layer for AR3 and AR4 systems is prepared by mixing various constituents in ratio TEOS: ethanol (ETOH): H2O : HCI: Zr-pro: IPA: 2-IPETOH of 30.61 : 39.51 : 19.76 : 0.12: 0.7: 7.98: 1.32 (wt.%). Composite sol of SiO2-TiO2 utilized for preparation of 2nd (top) layer for AR5 and AR6 systems is prepared by mixing various constituents in ratio TEOS: ETOH: H2O: HCI: Ti(OiPr), IPA: IPETOH of 30.61 : 39.51 : 19.76 : 0.12: 0.42: 8.22: 1.36 (wt.%). High refractive sols of both TiO2 and ZrO2 are each mixed for greater than or equal to 17 hours, during which time solutions undergo hydrolysis, polycondensation, and polymerization at a very slow rate, and low refractive sol of SiO2 with MPTS is mixed for 17 hours, and other 2 SiO2 composite sols (SiO2-TiO2 and SiO2-ZrO2) are mixed for 24 hours. Preferred Parameters: Thickness of bottom layer is 33-49 nm on glass substrate or 28-41nm on silicon substrate, preferably less than or equal to 50 nm. Thickness of top layer is 97-112 nm on glass or 82-143 nm on silicon wafer, preferably less than or equal to 150 nm. Refractive index of bottom layer is 1.7-1.8 on glass or 1.9 on silicon wafer, preferably less than or equal to 2. Top layer refractive index value is 1.3-1.46 on glass or 1.41-1.51 on silicon wafer, preferably less than or equal to 1.52. Haze value of AR bi-layer system on glass substrate is 0.12-1.03, preferably less than or equal to 1.1. Coating has maximum transmittance of 95.8-98.4% in visible range of 400-700 nm and average reflectance of less than or equal to 2.51% in complete active solar range of 300-1500 nm and can withstand less than or equal to 9H pencil hardness test.