The report studies the dependance of responsivity on the schottky barrier and the density of the surface states of the monolayer MoS₂ (grown on p-Si and n-Si). The density of surface states (Nss) were varied using nitrogen doping which also introduced p-type doping causing the variation in the schottky barrier height. Photodetection experiments were conducted, and observed an increase in responsivity from 63 A/W(undoped) to 606.37 A/W (doped) for n-Si or decrease from 572.35(undoped) A/W to 191 A/W (doped) for p-Si. It was also noted an increase in Nss from 1.5x10¹⁷ (undoped) to 1.8x10¹⁷ (doped) for p-Si and 4.47x10¹² (undoped) to 1.63x10¹³ (doped) for n-Si. It is evident that barrier height of 0.20eV for n-Si and 0.18eV for p-Si for a doped MoS₂ plays crucial role in changing responsivity. Also, with increase in temperature of the nitrogen doped MoS₂ device (grown on both substrates) it was noted that density of surface states decreases which further decreases the responsivity.