Novel synthetic methods in solution that reduce the formation temperature of bismuth-based electronic
oxides are essential for their successful integration with substrates of low thermal stability within microand
flexible-electronic devices. This has become crucial for these oxides, since they appear as promising
low-toxic functional materials alternative to other electronic oxides containing heavy metals. However,
this is a challenge, since the crystallization of bismuth oxides occurs at high temperatures. To overcome
these problems, we synthesize here a UV-absorber charge transfer metal complex in solution between
the Bi(III) ion and an alkanolamine, N-methyldiethanolamine (Bi(III)–mdea). We take advantage of the
photoreactivity of this complex to prepare bismuth-based oxide thin films at low temperature, which
cannot be achieved by traditional thermal processing methods. Room temperature stable oxide thin
films of the high-temperature d-Bi2O3 phase are prepared from these solutions by UV-irradiation and
annealing at 350 C. The efficiency of this synthetic strategy is additionally proven for the low
temperature preparation of thin films of much more complex bismuth based functional oxides: the
multiferroic bismuth ferrite, BiFeO3, and the relaxor-ferroelectric perovskite of bismuth, sodium and
barium titanate, (Bi0.5Na0.5)0.945Ba0.055TiO3