Effect of Sb and Si doping on the superconducting properties of FeSe0.9

► We synthesized all the samples using two-step solid state reaction method. ► Si and Sb doping is done at the Se site of the compound FeSe0.9. ► Hc2(0) is calculated with GL-Fit and also using WHH model. ► Behavior of activation energy is studied with applied field.