Phenomenological characterization of photoactive centers in Bi12TiO20 crystals

Jaime Frejlich (1) , Renata Montenegro (1) , Nilson R. Inocente-Junior (1) , Pedro V. dos Santos (1) , Jean-Claude Launay (2) , Christophe Longeaud (3) , Jesiel F. Carvalho (4)

1 Laboratório de Óptica
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 LGEP - Laboratoire de génie électrique de Paris
4 Instituto de Física

We report optical and electrical measurements contributing for a better characterization of the relevant photoactive center levels in undoped photorefractive Bi12 TiO 20
BTO crystals grown in Brazil. Comparative results for Pb-doped BTO and Bi12 GaO 20 are also reported. A center responsible for photochromism was identified at 0.42– 0.44 eV, probably below the conduction band
CB. The main electron and hole donor center is detected at 2.2 eV from the CB and the equilibrium Fermi level is pinned at this level. Other localized centers were identified at different positions in the band gap and their relation with the behavior of BTO under different wavelengths and operating conditions is discussed with particular attention to holographic recording.

Mots clés: Inorganic compounds; Bismuth; Titanium; BTO; Oxides; Crystal growth; Measurements

Domaines: Matériaux

Jaime Frejlich, Renata Montenegro, Nilson R. Inocente-Junior, Pedro V. dos Santos, Jean-Claude Launay, et al.. Phenomenological characterization of photoactive centers in Bi12TiO20 crystals. Journal of Applied Physics, 2007, 101 (4), pp.043101. ⟨10.1063/1.2434009⟩. ⟨hal-00133018⟩