Methods of forming high-current density vertical p-i-n diodes on a substrate are described. The methods include the steps of concurrently combining a group-IV-element-containing precursor with a sequential exposure to an n-type dopant precursor and a p-type dopant precursor in either order. An intrinsic layer is deposited between the n-type and p-type layers by reducing or eliminating the flow of the dopant precursors while flowing the group-IV-element-containing precursor. The substrate may reside in the same processing chamber during the deposition of each of the n-type layer, intrinsic layer and p-type layer and the substrate is not exposed to atmosphere between the depositions of adjacent layers.