The c-axis oriented thermoelectric Ca3Co4O9 thin films were prepared on sapphire (0001) substrates using pulsed laser deposition (PLD) technology. X-ray diffraction (XRD) was used to determine the micro-structure and orientation of Ca3Co4O9 thin films. The influence of substrate temperature and oxygen pressure on crystalline and orientation of thin films was investigated and the optimal conditions were determined. Optimal conditions were used to prepare Ca3Co4O9 thin films on vicinal-cut Al2O3 (0001) substrates. When the Ca3Co4O9 film was irridated by laser with wavelength of 248 nm, pulse bandwidth of 20 ns, the two ends of the film would induce thermoelectric voltages (LITV). And the peak voltage and response time at the two ends of the film can reach 4.4 V and 36 ns respectively. And the bandwidth of the voltage is 131 ns. The correlated mechanism of this phenomenon was discussed.