The fabrication of high-density ZnSe self-assembled quantum dots is important for high-efficiency blue-green laser diodes. ZnSe self-assembled quantum dots cannot be obtained on the high-strain ZnS/GaAs with the ZnS thickness of 15 nm, which is higher than its critical thickness 7 nm. ZnSe self-assembled quantum dots on 15, 57, 103, 130, and 160 nm ZnS/GaAs were studied. For 130 nm thick ZnS/GaAs, the density of ZnSe quantum dots can reach 4.9 x 10(9) cm(-2) for a fixed 30 s ZnSe growth. All photoluminescence spectra of ZnSe quantum dots show blue shifts but relative red shifts with the ZnS thickness of 57, 103, and 130 nm. The mechanisms were studied. (c) 2006 The Electrochemical Society.