Fig. 39.1 Optical absorption coefficient of CuInSe2 and Cu(InGa)Se2
1997). These experimental values agree with recently refined local density approximation calculations, which show anisotropy of the hole effective masses with a factor of 4 difference between parallel and perpendicular to the c-axis. CuInSe2 has the lower effective hole mass perpendicular to the c-axis (see Table 39.1).