HIGH-QUALITY GAAS EPITAXIAL LAYERS GROWN FROM GA-AS-BI SOLUTIONS BY LIQUID-PHASE EPITAXY

The liquidus isotherms for the Ga-As-Bi system were determined at 973 and 923 K in the Ga-As-GaAs region. The liquid phase epitaxial growth of GaAs from Ga-As and Ga-As-Bi solutions were investigated. The addit ion of ten atomic percent of Bi to the Ga-As solution increase the gro wth rate of the grown epilayers nearly 4.4 times than in the case of G aAs layers from Bi solution. Above 9 at.% of Bi in Ga solution the pro blems associated with the edge growth were almost eliminated. Optical measurements at 4.2K revealed that Bi does not alter the band gap ener gy value of the GaAs epitaxial layers. The photoluminescence (PL) inte nsity and full width at half maximum (FWHM) revealed the good quality of undoped GaAs epilayers from Bi solvents compared to that of Ga solv ents even though the purity of the Bi was relatively less.