Properties of InP self-assembled quantum dots embedded in In_0.49(Al_xGa_1-x)_0.51P for visible light emitting laser applications grown by metalorganic chemical vapor deposition

Abstract

We have studied the properties of InP self-assembled quantum dots embedded in various In_0.49(Al_xGa_1-x)_0.51P matrix layers to optimize the growth condition of the quantum dots and structures for III-phosphide quantum-dot-based lasers operating in visible spectral regions. Self-assembled quantum dot-related structures are grown by low-pressure metalogranic chemical vapor deposition and characterized by atomic-force microscopy, high-resolution transmission-electron microscopy, and photoluminescence. High density (~10¹⁰cm^-2) and conveniently sized (~5x20nm) quantum dots are produced by growth condition optimization. We find that the quantum-dot heterostructure with a In_0.49(Al_xGa_1-x)_0.51P matrix layer having the largest direct band gap produces the most efficient luminescence at room temperature. Laser structures are prepared using optimized growth conditions and matrix materials. Laser operation with lasing wavelengths λ =650-680nm are demonstrated at 77 and 300 K by optical pumping.