InAs/InP quantum dots emitting in the [formula omitted] wavelength region by inserting ultrathin GaAs and GaP interlayers

Abstract

We present an effective method to tune the emission wavelength of InAs/InP(1 0 0) quantum dots (QDs) in the 1.55 μ m wavelength region. The InAs QDs are embedded in lattice-matched GaInAsP which is the waveguide core material in InP-based photonic devices. By inserting ultrathin GaAs (0.3–2.5 monolayers (MLs)) or GaP (0.3–1.1 MLs) layers between the QDs and the GaInAsP buffer, continuous wavelength tuning from above 1.60 μ m to below 1.5 μ m at room temperature is demonstrated by varying solely one growth parameter, i.e., the interlayer thickness. The thin GaAs and GaP interlayers play an important role in suppressing As/P exchange and consuming surface-segregated In, leading to drastic reduction of the emission wavelength of the InAs QDs.