A silicon based light emitting diode (LED) is a new gateway for combining optoelectronics with CMOS integrated circuits. The choice of silicon is limited due to its indirect band gap nature. There are new approaches for improving emission efficiencies in Si-LED to nearly 1% at room temperature. Boron implantation has been employed to introduce dislocation array and as a p-type dopant to form p-n Junction in an n-type Si substrate. The device operates as a conventional LED under forward bias. The temperature dependence of radiative recombination rate is addressed by Varshni empirical formula. The difference between the energy at which maximum light emission occurs and the energy gaps at the measurement temperature is found to be a constant. The dislocation arrav density, Junction depth. defect structure for silicon and silicon based alloys are investigated. Mechanisms of light confinement are studied. Photo luminescence (PL) and electro luminescence (EL) measurements are studied to ensure that the LED output arises from Si band-edge radiative recombination of confined carriers.