Crystal Growth, Structural Characterization and Room Temperature Band Gap of CuIn3Se5 and CuGa3Se5.

X-ray powder diffraction studies of CuIn₃Se₅ and CuGa₃Se₅, the end members of the Cu(In_1-xGa_x)₃Se₅ semiconducting system, show that these compounds present a tetragonal chalcopyrite-related structure. The unit cell parameters a and c are 5.7541(5) and 11.538(3)Å for CuIn₃Se₅ and 5.4995(8) and 10.946(3)Å for CuGa₃Se₅. Bulk samples of both CuIn₃Se₅ and CuGa₃Se₅ exhibited n-type conductivity with the average energy band gap at room temperature being 1.154 and 1.754 eV, respectively.