Group-III nitride based heterostructures contain an internal electric field that results in a reduced overlap of the wavefunctions of electron and hole and is the main reason for a low quantum effi- ciency. We examine GaN/InGaN quantum wells (QW) and apply external stress in order to vary the internal piezoelectric fields and thereby influence the optical properties of the quantum wells.
We measure time resolved photoluminescence (TRPL) and perform pump probe (PP) experiments on single and multiple GaN/InGaN quantum wells under varied strain that is applied uniaxial, along the growth direction with a pressure cell. Additionally we measure the spin dynamics via Kerr rotation to gain information on the internal electric fields since the spin dephasing rate is directly related to this fields via Rashba effect.
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