A solar cell comprises a three layer semiconductor structure wherein the top (14) and middle (15) layer are made of a semiconductor of higher bandgap than the bottom layer (16), the middle layer (15) has a higher dopant concentration than the top layer (14), and the three layer semiconductor structure is either a p-n-p structure or an n-p-n structure. The solar cell includes three terminals or contacts: a top contact (17) contacting the top layer (14), a middle contact (18) contacting the middle layer (15) and a bottom contact (19) contacting the bottom layer (16). Light anti-reflecting layers and semiconductor layers to reduce surface recombination can also be added to the basic three layer semiconductor structure.