CH3NH3PbI3 thin films prepared by pulsed laser deposition for optoelectronic applications

- We have prepared CH3NH3PbI3 films by on-axis deposition of PLD for the first time.
- The crystallinity and phase composition of the film rely on pulse repetition rates.
- The pure phase perovskite film has excellent crystallinity and optical absorption.
- We have fabricated a CH3NH3PbI3/n-Si heterojunction device for the first time.
- The device demonstrates good electrical characteristics and fast photoresponse.

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.