There is provided a quantum dot comprising a core comprising a semiconductor and a shell substantially covering the core. The core has a first side and a second side opposite the first side. The coreis disposed eccentrically inside the shell such that the shell is thinnest at the first side and thickest at the second side. Moreover, the shell has a thickness of greater than or equal to zero at the first side. The core and the shell have different respective lattice constants such that the shell exerts a straining force on the core. The straining force is configured to modify an excitonic finestructure of the core.