Fundamental absorption edge of thin films of Bi4Si3O12

The fundamental absorption edge of thin films of Bi₄Si₃O₁₂ is investigated. On the basis of its temperature dependence, exciton-phonon interaction is investigated, which made it possible to interpret the absorption edge as the absorption of autolocalized excitons. The temperature dependence of the forbidden band width is given. I. Franko Lvov State University, 50, Dragomanov St., Lvov, 290005, Ukraine. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 2, pp. 232–235, March–April, 1997.