A new self-assembled quantum dots system where InGaAs dots are formed on InAlAs wetting layer and embedded in GaAs matrix has been fabricated. The photolumines cence linewidth increases with increasing temperature, which is very different from normal In(Ga)As/GaAs quantum dots. The results are attributed to a higher e nergy of the wetting layer which breaks the carrier transfer channel between dot s and keeps the dots more isolated from each other.