Strain Relaxation Induced Red Shift of Photoluminescence of CdZnSe/ZnSe Quantum Wires

Wire patterns (80-1000 nm) of molecular beam epitaxy grown Cd$\text{}_{0.2}$Zn$\text{}_{0.8}$Se/ZnSe quantum well were fabricated by a CH$\text{}_{4}$/H$\text{}_{2}$ reactive ion etching technique. Photoluminescence emission shows with decreasing lateral size a broadening of line shape and a spectral red shift. Calculations for the change of the band gap due to strain relaxation show that this shift of the photoluminescence emission for narrow Cd$\text{}_{0.2}$Zn$\text{}_{0.8}$Se/ZnSe structures (lattice mismatch of 1.34%) can be explained by a partial elastic strain relaxation of the biaxially compressively strained Cd$\text{}_{0.2}$Zn$\text{}_{0.8}$Se quantum well after the patterning process.