Theoretical comparison of the band alignment of conventionally strained and strain-compensated phosphorus- aluminum- and nitrogen-based 1.3 mu m QW lasers

GONUL B., KOCAK F., TOKTAMIS H., Oduncuoglu M.

CHINESE JOURNAL OF PHYSICS, vol.42, no.6, pp.764-775, 2004 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 42 Issue: 6
  • Publication Date: 2004
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.764-775
  • Yıldız Technical University Affiliated: No


A comparative study of the band-offset ratio of the three competing laser materials, namely lnGaAsP/InP, AlGaInAs/InP, and InGaNAs/GaAs, has been undertaken for the first time, to show the usefulness of the strain-compensated quantum wells (QW) from the band alignment point of view. It was confirmed from our calculations that the alternative uncompensated AlGaInAs and InGaNAs laser systems have substantially better band alignment than that of the commonly used uncompensated InGaAsP. The detailed analysis of the effect of strain compensation on the band alignments of the three competing laser materials has shown that strain compensation brings further benefits to the alternative laser systems, especially to InGaNAs/GaAs. Therefore, high temperature operation has been anticipated in these alternative laser systems with a strain compensated barrier due to the better electron and hole confinement as a result of the increased band offset and a more favorable band offset ratio. In addition, the use of GaAsP barriers instead of AlGaAs barriers to provide strain compensation improves the band alignment, even in the uncompensated value of the InGaNAs/GaAs laser system. Moreover, the introduction of strain to the barrier into the InGaNAs/GaAs laser system causes the electron wells to be much deeper than that of the hole wells, which is essential for having good high temperature characteristics. Therefore, a strain-compensated InGaNAs/GaAs laser system can be offered as an ideal candidate for high temperature operation.