Effects of increased growth rate of well layer on 2.1% compressive strained InAsP-MQWs grown by metalorganic molecular beam epitaxy (MOMBE)

Abstract

Effects of growth rate on metalorganic molecular beam epitaxy (MOMBE) growth of 2.1% compressive strained InAsP-multi-quantum wells (MQWs) was investigated using photoluminescence (PL), double-crystal X-ray diffraction (DCXRD) analysis and cross-sectional transmission electron microscopy (XTEM). As the growth rate of a well layer increases from 0.17 to 0.33 nm/s, the PL intensity increases remarkably and the width of satellite peaks in the DCXRD spectra becomes narrower. The amplitude of a well layer surface undulation, ascertained by XTEM, decreases as the growth rate increases, simultaneously. This indicates that increasing of the PL intensity and narrowing of the satellite peak width are attributed to decreasing of amplitude of the well layer surface undulation caused by increasing the growth rate. Utilizing this finding, we can increase the number of strained InAsP wells up to 20 without any evidence of material degradation due to well layer surface undulation. In addition, we fabricated buried heterostructure MQW lasers emitting a 1.56 μm wavelength light with a low threshold current of 7.0 mA and a large differential gain of 9.0×10 −16 cm 2.