Abstract: The invention relates to a sunlight-guiding module (2) for a photobioreactor (1) comprising a reaction chamber (11), the module (2) comprising: —a concentrating device (21) placed outside the reaction chamber (11) in order to concentrate the sunlight into a concentrated beam; —a scattering device (24) placed in the reaction chamber (11); characterised in that the module (2) also comprises a homogenising device (22) placed between the concentrating device (21) and the scattering device (24) in order to make the concentrated beam homogeneous before the concentrated beam enters the scattering device (24). The invention also relates to a light-guiding panel (3) comprising at least two light-guiding modules (2). Finally, the invention relates to a photoreactor (1) comprising a reaction chamber (11), characterised in that it also comprises a light-guiding module (2) or panel (3).