Carbon modified (CM)-n-TiO2 thin film was synthesized and optimized by flame oxidation method at high temperature of 825{degree sign}C, and 16 min heating time. The natural gas and oxygen flow rates of 3.32 L/min and 2.23 L/min were found optimum to incorporate the appropriate amounts of carbon concentration in the bulk and on the surface of the CM-n-TiO2 thin films. TJ-a-Si solar cell biased CM-n-TiO2│2.5 M KOH │Pt PEC generated hydrogen gas of 25.0 L m-2 h-1 and a photoconversion efficiency of 5.45 % under the solar simulated light illumination of 1 sun. Importantly, the Tj-a-Si solar cell biased dark water electrolysis cell of Pt│2.5 M KOH │Pt in did not show any measurable H2 gas production. The monolithic Self-Driven n-TiO2 -Mn2O3 coated Tj-a-Si│2.5 M KOH │Pt PEC generated hydrogen gas of 15.63 L m-2 h-1 and a photoconversion efficiency of 4.16 %. This PEC was found to last more than 5 hours (compared to maximum 5 min life time for uncoated Tj-a-Si│2.5 M KOH │Pt PEC). This limited stability for 5 hours was attributed to presence of some pin-holes on n-TiO2-Mn2O3 coated Tj-a-Si solar cell surface.