RE3+(RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) doped Gd2SiO5 optoelectronic materials were synthesised by solid state diffusion method and their down conversion spectral properties were reported in this paper as function of different RE3+ concentrations. The solid state diffusion results in well crystallized phosphor particles. The prepared materials were characterized by XRD, FT-IR, photoluminescence (PL) and CIE color co-ordinates techniques. Spectroscopic investigation revealed that gadolinium oxyorthosilicate (GSO), Gd2SiO5 phosphor doped with Ce3+ shows broad band emission with peak at 390 nm and 440 nm when excited at 350 nm excitation. Gd2SiO5:Dy3+ shows efficient blue and yellow band emissions at 481 nm and 576 nm Gd2SiO5:Eu3+ phosphor shows an orange and red emission at 587 nm and 615 nm respectively. Whereas Gd2SiO5:Tb3+ phosphor shows weak blue emission at 487 nm and strong green 545 nm. The excitation spectra used for the Gd2SiO5:RE3+ (where RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) phosphor are in the near UV (nUV) region extending from 250 to 400 nm, which is characteristics of modern lighting and display fields applications. The effect of the RE3+ (RE3+ = Ce3+, Dy3+, Eu3+ and Tb3+) concentration on the luminescence properties of Gd2SiO5:RE3+ optoelectronics materials were also studied. The investigated prepared Gd2SiO5 phosphors may be suitable for lighting based devices.