[[V001/JSI/Arhiv|{{attachment:Rubrike/T904.jpg|News Archive|width="350px"}}|&do=get]]

Researchers from F3 and F7 Departments of the Jožef Stefan Institute in collaboration with researchers from the Faculty of Mechanical Engineering, University of Ljubljana and Coimbra University (Portugal) investigated in the picosecond excitation regime the photoacoustic (PA) response of composite material made of graphene or graphene decorated with gold nanoparticles (AuNP) and polydimethylsiloxane (PDMS). AuNP attached to graphene improve the dispersibility of the flakes in the polymer, increase the surface area in contact with the polymer, and prevent the re-adhesion. All of this leads to a better intercalation of the polymer with the graphene flakes and a more uniform and efficient generation of PA waves. By using picosecond excitation of the graphene-based composite, we measured PA waves with bandwidths of 70 MHz and 130 MHz at -6 dB and -20 dB. The peak pressures of the PA waves achieve values > 5 MPa. The bandwidth can be further increased to values of 85 MHz at -6 dB and 135 MHz at -20 dB by decorating the graphene with AuNP. The results of the research were published in the journal [[https://www.sciencedirect.com/science/article/pii/S2211285524009881?via%3Dihub|Nano Energy]] and EU patent was granted.