The Photoacoustic Effect of Multilayered Graphene Films

Abstract

This paper presents a theoretical model of the photoacoustic effect for mutilayered graphene films based on the photoacoustic theory of solids and the thermoacoustic theory of graphene films. The expression of sound pressure of the photoacoustic signal from a mutilayered graphene film is therefore derived according to the theoretical formula. An acoustic platform is built to measure the output sound pressure generated by graphene film on a polyethylene terephthalate (PET) substrate, and the experimental values are compared with the corresponding theoretical values. The results show that the trends of the two in the frequency domain are identical, thereby validating the proposed theoretical model. The graphene film speaker has a wide range of frequency response, and the output sound pressure of the film varies linearly with the input optical power. In the far-field region below 17000 Hz, the output sound pressure of the film gradually rises with an increase of the incident light frequency under constant incident light power. The frequency response of the film is relatively stable in the near-field region by comparison.