CH₃NH₃PbI₃ thin films were prepared on glass substrates by pulsed laser deposition. The phase structural properties of the films deposited with different pulse repetition rates were analyzed carefully. The films deposited at 8 Hz and other rates show a single phase CH₃NH₃PbI₃ and mixed CH₃NH₃PbI₃-PbI₂ phases, respectively. The prepared CH₃NH₃PbI₃ film possesses absorption coefficients of 10⁴ cm⁻¹ in the visible region and the optical band gap of 1.66 eV. The CH₃NH₃PbI₃/n-Si heterojunction device was fabricated. The I-V characteristics of the heterojunction in the dark and under illumination exhibit good rectifying behavior and fast photoresponse. The rise and fall time of the device were measured to be 58.8 μs and 1.9 μs.