Bi2 O3

Bismuth oxide (Bi₂O₃) is an n-type semiconductor ceramic compound that exists in multiple crystal phases, with the cubic δ-phase being most relevant for electronic applications. It is primarily used in optoelectronic devices, gas sensors, photocatalysts, and emerging applications in solid oxide fuel cells (SOFCs), where its ionic conductivity and optical properties are leveraged. Bi₂O₃ is notable for its low bandgap energy and high dielectric constant compared to conventional semiconductors, making it attractive for applications requiring visible-light responsiveness or high-temperature ionic transport, though it remains less mature than established semiconductor platforms.