Photoluminescence and electron transport properties of silicon-doped Ga{sub}0.52In{sub}0.48P/GaAs grown using a valved phosphorus cracker cell in solid source molecular beam epitaxy

摘要

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 × 10{sup}18 cm{sup}(-3) and 3.2 × 10{sup}18 cm{sup}(-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 cm{sup}2/Vs within the range of electron concentration measured (4.5 × 10{sup}16 to 7.7 × 10{sup}18 cm{sup}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.