High purity SiO2 substrates were implanted by 45 keV Ti ions or sequentially implanted by 45 keV Ti and Cu ions at different fluences. After annealing at 900 °C, rutile TiO2 nanorods were synthesized in the samples sequentially implanted with Ti and Cu ions. Besides, strong room temperature exciton absorption was observed near the band edge of TiO2 in these samples. The position and intensity of the TiO2 exciton absorption peak can be regulated by changing the fluence of Ti and Cu ions. Finally, through analyzing the valence and distribution of elements of the samples, we put forward a possible mechanism about the formation of the surface polarized dipoles layer on the surface of TiO2 nanorods to explain the exciton-enhanced phenomenon. The experimental results provide an effective way to enhance the exciton absorption of TiO2, which could be used to fabricate more efficient optoelectronic devices.

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