Strong ultraviolet emission from SiO[sub 2]/LiNbO[sub 3](:Fe)/SiO[sub 2] structures.

SiO[SUB2]/LiNbO[SUB3](LN)/SiO[SUB2] sandwich structures were fabricated for exploring efficient light emission. After annealing at 1000 °C in O[SUB2] for 30 min, this kind of sandwich structure shows a strong ultraviolet photoluminescence (PL) with an asymmetric spectral shape. This PL spectrum may be Gaussian divided into two bands peaked at 310 (α-band) and 346 nm (β-band). If the layer of LN film is replaced by an Fe-doped LN (LN:Fe) one, the β-band vanishes and the α-band redshifts. The α-band is greatly enhanced and simultaneously becomes asymmetrical after this kind of SiO[SUB2]/LN:Fe/SiO[SUB2] structure is annealed for 60 min. Spectral analysis suggests that the α-band arises from an optical transition in positively charged E8 centers at the interfaces between the LN(:Fe) film and the two SiO[SUB2] layers, while the β-band arises from intrinsic defects in the LN(:Fe) films. The mechanism for the PL enhancement is discussed in terms of a photorefractive effect in the LN(:Fe) films. [ABSTRACT FROM AUTHOR]