Photoluminescence and electron transport properties of silicon-doped Ga0.52In0.48P/GaAs grown using a valved phosphorus cracker cell in solid source molecular beam epitaxy

We report the transport and photoluminescence (PL) properties of silicon-doped GaInP layers grown on GaAs(100) substrate using a valved phosphorus cracker cell in solid source molecular beam epitaxy (SSMBE). Within the range of silicon (Si) effusion cell temperature investigated (900 to 1200°C), the highest electron concentration obtained was 7.7×10¹⁸ cm^-3 and 3.2×10¹⁸ cm^-3 at room temperature and 77 K, respectively. The concentration decreased with further increase in the silicon cell temperature. The Hall mobility at 300 K varied from 356 to 1720 cm² /Vs within the range of electron concentration measured (4.5×10¹⁶ to 7.7×10¹⁸ cm^-3). Except for the sample grown at the highest silicon cell temperature (1200°C), the PL spectrum of other samples showed a dominant peak attributed to Si donor-to-band transition (D-B), which shifted to higher energy following an increase in the electron concentration. This phenomenon was attributed to the Burstein-Moss effect. The blue shift of the (D-B) transition peak at increasing temperature was attributed to thermal ionization of the Si donors. The sample grown at the highest Si cell temperature showed a PL, peak at ~1.913 eV which was attributed to transition between the conduction band and Si acceptor (B-A), with an activation energy of ~57.2 meV as deduced from the PL spectrum. Temperature-dependent Hall measurements confirmed the amphoteric behaviour of the Si dopant in this sample