Bandfilling in liquid phase epitaxial InPhyphen;In1minus;xGaxP1minus;zAszhyphen;InP quantumhyphen;well heterostructure lasers

摘要

The bandfilling and gain behavior of thin (Lzsim;400 Aring;) In1minus;xGaxP1minus;zAsz(xsim;0.13,zsim;0.29) layers imbedded in InPphyphen;njunctions, or on one side of the active region of regular quaternary double heterojunctions (xsim;0.09,zsim;0.20), are described. Bandfilling and spontaneous emission are observed from the quaternary quantumhyphen;well band edge to the band edge of the InP confining layers (Dgr;Egsim;245 meV, 77 K). Laser operation on confinedhyphen;particle transitions can be observed in the range 0hngr;minus;Eg(InGaPAs) lsim; (2/3) Dgr;Eg. The reduced gain of a quantumhyphen;well heterostructure is demonstrated by comparison with the behavior of conventional quaternary double heterojunctions (active layer gsim;0.1 mgr;m) grown from the same set of LPE melts. To operate as lasers quantumhyphen;well heterostructures are shown to require greater diode lengths and higher excitation currents, consistent with large bandfilling (in a thin layer) leading to a large spectral spread in the recombination radiation. These effects are demonstrated also on quaternary double heterojunctions of standard activehyphen;layer thickness (gsim;0.1 mgr;m) but modified with the inclusion of a quantum well on one side of the active region.