Characterization of Si-doped GaInAsP/GaAs grown by solid source molecular beam epitaxy

We report growth and characterization of the Si-doped GaInAsP, lattice-matched to GaAs substrate, grown by solid source molecular beam epitaxy using a valve phosphorous cracker cell. It is found that the electron concentration increases with the temperature of Si effusion cell until 1150 degree C and decreases as the Si-cell temperature is increased further, due to the amphoteric behavior of Si. The Hall mobility follows the same trend except it reaches the maximum at a lower temperature. The Raman results reveal that the GaP-like LO mode of the materials decreases and the InP-like LO mode increases with the Si-cell temperature. It indicates that the excess Si may occupy the P site rather than As sites for p-type conduction. In addition, it is also found that Si doping has no significant influence on the lattice mismatch and has surface roughness.