Growth and material properties of InPBi thin films using gas source molecular beam epitaxy

The effects of Bi, In flux and PH₃ pressure on Bi incorporation, structural and transport properties of InPBi grown by gas source molecular beam epitaxy have been systematically studied. Incorporation of Bi behaves like a dopant and its content increases linearly with Bi flux and inversely with the InP growth rate (In flux), and is independent of the PH₃ pressure studied. High PH₃ pressure causes rough surface and introduction of Bi improves surface quality. Intrinsic InP grown at a low temperature reveals n-type due to the P_In antisite defects and the electron density is proportional to the PH₃ pressure and inversely proportional to the InP growth rate. Incorporation of Bi induces p-type dopant that compensates the background electron concentration but doesn't degrade the electron mobility for the Bi content up to 2.4%. These results suggest that there is still a large room left to optimize material quality and maximize Bi incorporation in InPBi using gas source molecular beam epitaxy. - Highlights: • The effects of Bi, In and PH₃ flux on material properties of InPBi have been systematically studied. • Incorporation of Bi behaves like a dopant and is independent of the PH₃ pressure studied. • The electron concentration is modeled by considering the decreasing effect due to Bi incorporation.