REEVALUATION OF BLUESHIFTS INTRODUCED BY LATERAL CONFINEMENT IN QUANTUM-WELL WIRE STRUCTURES

The luminescence from etched quantum-well wire structures often exhibits an unexpectedly large blueshift of the peak energy position. Further, the shift is usually quite independent of the width of the wires. In this letter we show that this blueshift can be explained as a decreased transfer of excitons between areas of different monolayer thicknesses within the single quantum wells, caused by a change in the exciton diffusion from being two-dimensional in the quantum wells to one-dimensional in the wires. This reduced transfer will result in a blueshift of the peak energy position if the monolayer splitting is unresolved.