InAsSb/InGaAs quantum nanostructures on InP (100) substrate: observation of 2.35 µm photoluminescence

Abstract

A theoretical and experimental study of the electronic properties of InAsSb quantum dots (QDs) grown on InP substrate is presented. Unstrained bulk InAsSb presents a direct gap between 0.1 eV to 0.35 eV, suitable for mid infrared emitters (3-5 µm). However, strain and quantum confinement effects may limit the extension of the emission spectrum of these nanostructures towards longer wavelengths. Various combinations of barrier materials are considered in the simulations. 1 Introduction Efficient semiconductor lasers emitting in the mid infrared range (3-5 µm) at room temperature (RT) have great potential in applications such as laser radar, military countermeasure, pollution monitoring and molecular spectroscopy. Laser diodes based on GaInAsSb/AlGaAsSb type I quantum wells (QW) exhibit excellent RT characteristics and emission wavelengths as long as 2.7 µm [1, 2]. At longer wavelengths (8-12 µm range) quantum cascade (QC) lasers based on transitions between confined states within the conduction band have shown continuous emission at RT [3]. However, the realisation of QC lasers emitting at short wavelengths at RT is challenging in conventional AlInAs/GaInAs structures, due to the limited conduction band offset in this material system [4]. Finally, commercial applications of such lasers may be restricted by the use of unconventional GaSb substrates and the complexity of the QC laser growth [5].On InP substrates, the technologically-matured InGaAsP QWs system is limited to 2 µm optical wavelength [6]. This spectral barrier can be broken by the incorporation of Sb, which decreases the band gap. Moreover, these nanostructures are promising for improving optoelectronic devices such as lasers or photodetectors. In particular, discrete energy levels and strong spatial confinement properties are expected to realize QD semiconductor lasers with low threshold current density, high differential gain and no temperature dependence [7]. Quantum dot (QD) formation allows to accommodate a large lattice mismatch without dislocation formation. Consequently, in order to extend the wavelength emission on InP substrates beyond 2 µm, we propose to use InAsSb QDs. Laser emission from InAsSb QDs grown on InP have been recently reported at 1.96 µm [8]. More, InAs in a well (DWELL) lasers based on InP at

Engineering the composition, morphology, and optical properties of InAsSb nanostructures via graded growth technique

“…These nanostructures have potential applications in mid-infrared optoelectronic devices. [8][9][10][11][12] It is found that by using different graded approaches the actual Sb composition in InAsSb nanostructures can be changed significantly despite the fact that their nominal Sb mole fraction (averaged over the graded growth) is kept the same, which results in different morphologies for the InAsSb nanostructures. As a result of their composition and morphological changes, photoluminescence from these InAsSb nanostructures shows different polarization and temperature characteristics.…”

Strain relaxation and phonon confinement in self-assembled InAsSb/InP (001) quantum dashes: Effect of deposition thickness and composition

“…In the past several years, self-assembled InAsSb nanostructures such as quantum dots ͑QDs͒, quantum dashes ͑QDashes͒, and quantum wires ͑QWRs͒, have attracted much attention due to their potential as midinfrared emitters for applications in military, telecommunications, molecular spectroscopy, biomedical surgery, environmental protection, and manufacturing industry. [1][2][3][4][5] Compared with In͑Ga͒As nanostructures on GaAs or InP substrates, these InAsSb nanostructures have much smaller island sizes ͑ϳ1 -3 nm in height͒ due to the large lattice mismatch between InAsSb and GaAs or InP materials. [5][6][7][8] The large strain and strong spatial confinement ͑induced by the small island height͒ in this material system will have a significant influence on the optical and electronic properties of these InAsSb nanostructures, and thus their device performance.…”

Emission wavelength extension of mid-infrared InAsSb/InP nanostructures using InGaAsSb sandwich layers

“…In recent years, InP-based InAsSb nanostructures have attracted considerable attention due to their potential applications as mid-infrared emitters (2-3 µm) [1][2][3][4][5]. Some work has been done on the direct growth of InAsSb nanostructures, where As and Sb atoms are deposited simultaneously with In atoms [5][6][7][8].…”