A dot-in-well structure for quantum dot (QD) growth on InP(001) vicinal substrates was introduced to increase the emission wavelength. The emission wavelength of QDs changed from 1600 nm, in conventional structures, to 1850 nm, in the proposed dot-in-well structure, when measured at room temperature. The emission intensity of this dot-in-well structure was the same as that of the conventional structure, implying that the dot-in-well structure did not degrade crystal quality.