Emission at 1.42 µm from InAs/GaAs Trilayer Quantum Dots

摘要

InAs/GaAs bilayer quantum dots (QDs) have attracted much attentionbecause ofits potential in extending emission wavelength of GaAs-based QDs fromwell-developed O-band to C-band. InAs/GaAs QD lasers based on bilayer structurehave been reported lasing at 1.34μmwithoutInGaAs strain-reducing layer (SRL). InAs/GaAs bilayer QDs without In GaAs SRL have been reported emittingat 1.4μmat room temperature (RT). In order to further extend the emission wavelength, we previously proposed a new structure named InAs/GaAs trilayer QDs. Inthis report, we demonstrated emissionat 1.42μmfrom InAs/GaAs trilayer QDs without InGaAs SRL which was longer thanthelongest reported wavelength of the bilayer QDs. The basic structure of InAs/GaAs trilayer QDs consists of three QD layers and two spacer layers. These QD layers are named as seed layer1 (SL1),SL2 andactive layer(AL).The strain field generates after growingtheSLsand contributes toreducing thestrain in the AL.It leads to the extension of emission wavelength of QDs in the AL which is optically active in thetrilayer structure.Comparing to the bilayer QDs, the strain in theALis further reduced due to the increased SLs.