Abstract
We used low-temperature near filed photoluminescence (PL) spectroscopy to study emission properties of self-assembled InGaAs/GaAs quantum dots (QDs) under nanoindentation by an optical fiber probe. The significant energy shifts as high as 100 meV of QDs emission induced by nanoindentation were observed. In order to clarify its mechanism, a three-dimensional FE model was developed to analyze the strain distribution of the QDs due to lattice mismatch and nanoindentation. Then, based on a six-band strain-dependent k・P Hamiltonian, the influence of strain on energy shifts was investigated. Both experiment and simulation results indicated the linear dependence of energy shift on indentation force and they agreed well with each other. Finally, the exchange of the top valence band between heavy hole and light hole band was discussed based on the six-band strain-dependent k・P Hamiltonian, the results supported the change of slope between the case with lattice mismatch and the case without it in the indentation simulation.
