Growth and characterization of an Al-doped GaSe crystal

A GaSe: Al (0.13 wt%) single crystal was grown using the Bridgman method combined with a crucible rotation technique. A 35 × 19×5.5 mm3 sample was cut from the as-grown crystal ingot. The GaSe: Al (0.13 wt%) crystal has an indentation hardness of 2.27 GPa, which is 2.6 times harder than the pure GaSe crystal. In particular, a sample with a thickness of 5.5 mm has an infrared transmission of approximately 60%. The absorption coefficient of this sample is as low as 0.1 cm−1 over the range of 0.83 to −14 μm, which demonstrates its high optical quality. A crystal growth method with the described procedures may be suitable to grow other doped GaSe crystals.