Abstract
We report the growth and optical characterization of single-crystal BiFe(1-x)Mn(x)O(3) thin films directly on SrTiO(3)/Si(001) substrates using molecular beam epitaxy. X-ray diffraction confirmed epitaxial growth, film crystallinity, and sharp interface quality. Scanning electron microscopy and energy dispersive X-ray spectroscopy verified uniform film morphology and successful Mn incorporation. Spectroscopic ellipsometry revealed a systematic bandgap reduction with increasing Mn concentration, from 2.7 eV in BiFeO(3) to 2.58 eV in BiFe(0.74)Mn(0.26)O(3), consistent with previous reports on Mn-doped BiFeO(3). These findings highlight the potential of BiFe(1)₋(x)Mn(x)O(3) films for bandgap engineering, advancing their integration into silicon-compatible multifunctional optoelectronic and photovoltaic applications.