Techniques for employing different channel materials within the same CMOS circuit are provided. In one aspect, a method of fabricating a CMOS circuit includes the following steps. A wafer is provided having a first semiconductor layer on an insulator. STI is used to divide the first semiconductor layer into a first active region and a second active region. The first semiconductor layer is recessed in the first active region. A second semiconductor layer is epitaxially grown on the first semiconductor layer, wherein the second semiconductor layer comprises a material having at least one group III element and at least one group V element. An n-FET is formed in the first active region using the second semiconductor layer as a channel material for the n-FET. A p-FET is formed in the second active region using the first semiconductor layer as a channel material for the p-FET.