A novel structure, which is both a lattice‐matched heterostructure and a Schottky barrier, is fabricated by epitaxial growth of (111) oriented HgSe on (0001) oriented CdSe. Hydrogen transport CVD is used, with a HgSe source temperature of 420°C and a CdSe substrate temperature of 330°C. Single crystal growth was obtained. Of the two orientations possible for the crystal symmetries involved, only one was observed for a given specimen. The ’’Schottky barrier’’ height for this lattice‐matched heterostructure is 0.73±0.02 eV as measured by the photoresponse method. This uncertainty is substantially less than is usual for Schottkies. The magnitude is greater by about one‐quarter volt than is achievable with the most electronegative elemental metal, Au, in qualitative agreement with work function arguments.