Energy Transfer Between Bi[sup 3+] and Pr[sup 3+] in Doped CaTiO[sub 3]

CaTiO 3 : Pr 3 + shows strong red emission at 612 nm from 1 D 2 to 3 H 4 transition of Pr 3 + . Absorption by the 5d state lies in the long-wavelength side of the UV range. Co-doping with Bi 3 + greatly enhanced UV excitation in the spectral range 370-390 nm in which GaInN light-emitting diodes may emit. Doping with 5% Bi and 5% Al, the maximum UV excitation peak moved to 370 nm, and the absorptions at 380 and 390 nm were increased to 90 and 75% of the maximum absorption, respectively. It was found that the 1 S 0 → 3 P 1 absorption transition of Bi 3 + was quite strong and spanned a UV spectral range similar to the d-bands of Pr 3 + . The enhancement of UV excitation is attributed to energy transfer from Bi 3 + to Pr 3 + , and Bi 3 + plays a role as a sensitizer. © 2003 The Electrochemical Society. All rights reserved.