Despsite many efforts undertaken by the semiconductor scientific community, the demonstration of room-temperature laser source electrically pumped monolithically grown on silicon substrate is still an important challenge [1]. Amongst III-V semiconductors, GaP appears as a promising candidate thanks to its small lattice mismatch with Si [2]. Nevertheless, devices based on GaP materials need to deal with the difficulty to obtain efficient active area due to its indirect character. To overcome this, (In,Ga)As quantum dots (QDs) [3] were proposed. In this contribution, Influence of indium content on structural and optical properties is investigated in order to promote the direct optical transition of QDs. Four nominal In content: 10, 25, 35 and 50% of (In,Ga)As/GaP QDs grown by solid source molecular beam epitaxy (SS-MBE) on GaP substrate are analyzed by photoluminesence and atomic force microscopy (AFM) experiments. Significant redshift is reported in comparison between QDs with 10% to 35% of In content due to the valence band modification [4]. Moreover, it is shown that, while for low In contents a monomodal QDs distribution is observed [Fig1.a], a bimodal one appears for In contents reaching 35% and beyond [Fig1.b]. Controlling this distribution is a great challenge for obtaining a direct bandgap emission with GaP-based materials. This research project is supported by the Labex Cominlabs project: "3D Optical Many Cores" and the OPTOSI ANR project N°12-BS03-002-02. [1]C. Cornet, Y. Léger, et C. Robert, Integrated Lasers on Silicon. ISTE-Elsevier, 2016. [2]Y. Furukawa, H. Yonezu, A. Wakahara, S. Ishiji, S. Y. Moon, et Y. Morisaki, « Growth of Si/III–V-N/Si structure with two-chamber molecular beam epitaxy system for optoelectronic integrated circuits », J. Cryst. Growth, vol. 300, no 1, p. 172‑176, mars 2007. [3]M. Heidemann, S. Höfling, et M. Kamp, « (In,Ga)As/GaP electrical injection quantum dot laser », Appl. Phys. Lett., vol. 104, no 1, p. 11113, janv. 2014. [4]C. Robert et al., « Electronic, optical, and structural properties of (In,Ga)As/GaP quantum dots », Phys. Rev. B, vol. 86, no 20, p. 205316, nov. 2012.