A method for bandgap shift and phase transformation for titania structures. The method can include providing a flexible substrate, depositing a titania film onto the substrate, and exposing the titania film to one or more pulses of infrared energy of sufficient energy density and for a sufficient time to crystallize the titania film to predominantly anatase crystalline phase. The flexible substrate can be formed from a polymeric material, and the method can achieve a bandgap shift from greater than 3.0 eV to approximately 2.4 eV. The method can also include forming a crystalline titania layer over a substrate and annealing the crystalline titania layer by applying pulsed thermal energy sufficient to modify the phase constitution of the crystalline titania layer. The source of pulsed thermal energy can include an infrared flashlamp or laser, and the resulting titania structure can be used with photovoltaic and photoelectrolysis systems.