GaInAsP grown on GaAs substrate by solid source molecular beam epitaxy with a valve phosphorous cracker cell

GaInAsP epilayers grown on GaAs substrate by solid source molecular beam ep itaxy with a valve phosphorous cracker cell at varied arsenic beam equivale nt pressure ratio, f(As)/(f(As)+f(P)), were investigated. It is found that the InGaAsP/GaAs can be easily grown with the solid sources, and the incorp oration rate of arsenic is higher than that of phosphorous and varies with arsenic to phosphorous beam equivalent pressure (BEP) ratio, f(As)/(f(As)+f (P)). The lattice mismatch, Delta a/a(s), varies from negative to positive linearly with BEP ratio and follows a polynomial expression with arsenic co mposition. GaP-, InP-, GaAs-, and InAs-like LO modes are observed in all sa mples and shift as expected. The GaP- and InP-like TO mode is observed in m ost of the samples while the GaAs-like TO mode is observed only in the samp le with an arsenic composition of 0.96. Photoluminescence measurements reve al that the luminescence peak energy of the materials does nut change signi ficantly at high arsenic composition but increases drastically with the dec rease of arsenic composition. The full width at half maximum is found to be the largest in the sample with peak energy of 1.75 eV due likely to cluste r formation. All samples studied show smooth surfaces. (C) 2000 American Va cuum Society. [S0734-211X(00)05804-2].