Improved performance of 1.3μm multilayer InAs quantum-dot lasers using a high-growth-temperature GaAs spacer layer

Abstract

The use of a high-growth-temperature GaAs spacer layer is demonstrated to significantly improve the performance of 1.3μm multilayer self-assembled InAs∕InGaAs dot-in-a-well lasers. The high-growth-temperature spacer layer inhibits threading dislocation formation, resulting in enhanced electrical and optical characteristics. Incorporation of these spacer layers allows the fabrication of multilayer quantum-dot devices emitting above 1.3μm, with extremely low room-temperature threshold current densities and with operation up to 105°C.

A novel approach to increase emission wavelength of InAs/GaAs quantum dots by using a quaternary capping layer

“…This GaAs layer is grown at an ele− vated temperature (590 o C), and is called a high growth tem− perature spacer layer (HGTSL). At this temperature, gal− lium adatoms have a high mobility which leads to plana− rising the growth front for subsequent layers [3,14]. It has been shown that a GaAs HGTSL can planarise QD growth front only if its thickness is greater than a critical limit [15,16].…”

“…Electronic coupling in such a quantum dot superlattice leads to the formation of an intermediate band which can potentially improve the spectral response of solar cells [2]. MQDs are also useful in enhancing the perfor− mance characteristics of GaAs based quantum dot lasers [3]. However, typically, the emission wavelength of InAs/GaAs QDs (about 900 nm to 1100 nm) is shorter than the wave− lengths required in communication devices [1,[4][5][6].…”

Quantum Dot Superluminescent Diodes for Optical Coherence Tomography: Device Engineering

“…Waveguiding was provided by doped Al 0.4 Ga 0.6 As cladding layers. The details of the epitaxial growth can be found in previous reports on QD laser epitaxy development [17]. Fig.…”

Wide-Bandgap InAs/InGaP Quantum-Dot Intermediate Band Solar Cells

“…All the layers were grown at 495 C measured from a pyrometer. After capping each layer of InAs QDs with 6 nm Al 0.33 Ga 0.67 As, the substrate temperature was increased to 600°C and annealed for 2 min to suppress threading dislocation formation [20]. The first and last QD-layers are separated by 100 nm-thick In 0.49 Ga 0.51 P layers from the p-and n-emitters, respectively, in order to prevent carrier tunneling from the QDs to the CB in the emitters [7], [21].…”