Comparison of the photoluminescence spectra between quantum well structure and quantum dots structure

We have compared the photoluminescence (PL) spectra of InAs/InGaAsP/InP quantum dots (QD) structures with that of InGaAs/InP quantum well (QW) structures by changing the incident angle for TE polarized excitation light. From the results, we have found the shift of the PL peak wavelength is different between QD and QW. Then, we have measured the change in the FWHM of the PL spectrum against the excitation light intensity. The increment rate of the FWHM for QD is larger than that for QW. From the above, we have supposed each QD couples electrically to form a continuous band structure and the quantum levels broaden, due to adjacent QD whose size are variant. It means the band filling effect for the bulk sample occurs in QD samples.