A nano-TiO2, electrode with a p-n homojunction device was designed and fabricated by coating of the nano-TiO2 (n-type) film together with the Cr3+-doped TiO2 (p-type) film. The sample films were prepared with synthesized sol-gel TiO2 which were verified as nano-size particles with anatase structure. The semiconductor characteristic of the p-type and n-type films was analyzed by current-voltage (I-V) measurements. Results show that the rectifying characteristic of the TiO2 films was observed from the I-V data illustration for both the n-type and p-type films. In addition, the characteristic of the rectifying curves was influenced by the fabrication conditions of the sample films, such as the doping concentration of Cr3+ heating temperature of the films, and film thickness. From the I-V analysis, the rectifying current of this diode showed a 10(2) mA order higher than the one of the n-type film. The p-n homojunction TiO2 electrode showed greater performance of electronic properties than the n-type TiO2 electrode. (c) 2007 Elsevier B.V. All rights reserved.