NOVELTY - At least a first layer and a second layer of a semiconductor based material is electrodeposited onto a substrate layer by, in respect of the layer to be deposited, selecting pre-determined conditions including a pre-determined deposition voltage level to ensure that deposition of the layer results in the layer having a pre-determined electrical characteristic.    USE - The inventive method is for electrodepositing at least a first layer and a second layer of a semiconductor based material onto a substrate layer. It is for producing a semiconductor device (claimed) comprising the photovoltaic device; junction device(s) from the set of devices having a p-n junction, a p-i-n junction and a heterojunction; first and second junction devices; a solar cell; and an optoelectronic device.    ADVANTAGE - The inventive method is a low cost method that enables the doping level of semiconductor layers being deposited to be varied in a relatively straightforward manner. It establishes the growth of the semiconductor layers from the same electrodeposition bath composition such that the deposited layers are doped to different and predetermined degrees by varying the deposition voltage.    DETAILED DESCRIPTION - Electrodeposition of at least a first layer and a second layer of a semiconductor based material onto a substrate layer includes selecting a required semiconductor based material to be deposited; in accordance with pre-determined conditions specific to the selected semiconductor based material, configuring an electrodeposition bath arrangement to effect successive deposition of each of the layers on to the substrate layer; and in respect of the layer to be deposited, selecting the pre-determined conditions, including a pre-determined deposition voltage level, to ensure that deposition of the layer results in the layer having a pre-determined electrical characteristic.    DESCRIPTION OF DRAWING(S) - The figure schematically illustrates a 12-layer graded band gap solar cell structure fabricated with a p-type window material.