Microscale phenomena in bulk GaAs crystals: The effect of thermal gradients

摘要: Abstract Undoped bulk crystals of gallium arsenide were grown in a unique Bridgman apparatus. The effect the temperature gradient impressed over melt, conjunction with role melt composition (arsenic source temperature), was investigated. Crystals photo-etched to produce interface striation patterns and defect structures characteristics growth conditions. At low gradients found be sharply curved, but uniform electron-beam induced current cathodoluminescence intensities observed. As increased became flatter, uniformity EBIC CL signals deteriorated. Growth from nonstoichiometric melts resulted dislocation densities, yields Ga : ratio melt. Deep level populations also observed respond variations composition.