The invention relates to a method of depositing Hg_1-xCd_xTe onto a substrate, in a MOVPE technique, where 0x1; comprising the step of reacting together a volatile organotellurium compound, and one or both of (i) a volatile organocadmium compound and (ii) mercury vapour; characterised in that the organotellurium compound is isopropylallyltelluride. The invention also relates to devices, such as infrared sensors and solar cells, that comprise Hg_1-xCd_xTe materials.