A Si 1− xGe x/Si single quantum well p-i-n structure grown by solid-source and gas source “hybrid” Si molecular beam epitaxy

Abstract

By means of “hybrid” Si molecular beam epitaxy (MBE), an n-type Si contact layer for an electroluminescent (EL) p-i-n diode was successfully regrown on a Si 1− x Ge x /Si single quantum well (SQW) layer. The starting undoped SQW layer was grown by gas-source MBE (GSMBE) using disilane (Si 2H 6) and germane (GeH 4), and the n-Si contact layer was regrown by using solid-source MBE after transferring the sample through the air. A (2×1) reconstruction was observed on a GSMBE-prepared Si surface even after the sample was exposed to air for 15 h. Evidence of the excellent quality of the EL p-i-n device was provided by the sharpest emission lines, ≈ 5.5 meV, ever reported in the EL spectra of an SiGe system.