Characterization of silicon-doped InP grown by solid-source molecular beam epitaxy using a valved phosphorus cracker cell

Abstract

Silicon (Si)-doped InP layers were grown by solid-source molecular beam epitaxy and characterized by Hall and low-temperature photoluminescence (PL) measurements. During the growth the Si effusion cell temperature was varied from 900 to 1200°C, and the electron concentration measured was between 3.5×10 16 cm −3 and 1.1×10 20 cm −3 at room temperature. The corresponding Hall mobility varied from 3670 to 442 cm 2/V s and 10 400 to 475 cm 2/V s at 300 and 77 K, respectively for different Si cell temperatures. The mobility values were found to be higher compared to n-type InP layers grown by other techniques. 5 K PL spectra showed two peaks for the undoped and low-doped InP layers corresponding to the neutral donor-bound exciton transitions (D 0–X) and the acceptor-related transitions (D–A), respectively. When the Si doping level was increased, the high-energy near-band recombination underwent a typical evolution exhibiting a broadened asymmetric peak, and the peak shifted to high energy that was attributed to the band filling effect. This peak shift compared well with the theoretical prediction based on the Burstein–Moss shift and the band gap narrowing effect.