Theoretical study of strain-dependent optical absorption in a doped self-assembled InAs/InGaAs/GaAs/AlGaAs quantum dot

• Tarek A. Ameen,
• Hesameddin Ilatikhameneh,
• Archana Tankasala,
• Yuling Hsueh,
• James Charles,
• Jim Fonseca,
• Michael Povolotskyi,
• Jun Oh Kim,
• Sanjay Krishna,
• Monica S. Allen,
• Jeffery W. Allen,
• Rajib Rahman and
• Gerhard Klimeck

Beilstein J. Nanotechnol. 2018, 9, 1075–1084, doi:10.3762/bjnano.9.99

• absorption; quantum qot filling; self-assembled quantum dots; semi-empirical tight-binding; sp3d5s* with spin–orbit coupling (sp3d5s*_SO); Introduction Self-assembled quantum dots are employed as light absorbers in many optoelectronic devices, such as quantum-dot infrared photodetectors (QDIPs) [1][2], and

• obtain correct biaxial strain ratios in quantum wells is shown here to improve the accuracy of quantum dot simulations as compared with experimental measurements. The Hamiltonian is constructed with semi-empirical tight-binding with 20-orbital sp3d5s* basis per atom, including spin–orbit interaction

• expressions for the strain components in quantum wells are = (aGaAs − aInAs)/aInAs and [24], where a is the lattice constant. Electronic structure and absorption The eigenstates of the system were calculated with a Hamiltonian constructed from semi-empirical tight-binding sp3d5s*_SO basis. The Slater–Koster