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) with 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 different 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-xInxAsySb1-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 structural 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 reserved.