Strong band gap narrowing in quasi-binary (GaSb)(1-x)(InAs)(x) crystals grown from melt

Large crystals of a quasi-binary semiconductor alloy (GaSb)(1-x)(InAs)(x) w ith x = 0.02-0.05 have been grown from melt for the first time. The family of quasi-binary crystals (GaSb)(1-x)(InAs)(x) grown and reported here are d ifferent from the conventional Ga1-xInxAsySb1-y quaternaries due to growth behavior and physical properties. Significant narrowing of the band gap was observed in these crystals compared to the conventional quaternary Ga1-xIn xAsySb1-y (with x = y). With an InAs content of about 2-5 at%, band gaps in the range of 0.6-65 eV have been demonstrated. The possible origins of the band gap narrowing (i.e., high bowing parameter) include chemical and stru ctural alterations in the grown crystals, resulting from the association of Ga-Sb and In-As in the melt. (C) 1999 Elsevier Science B.V. All rights res erved.