Abstract This work studies the modal gain from quaternary quantum dots (QD) structures at different mole fractions of the structure. The quaternary structures are more flexible in attaining lattice‐matching systems. First, the In‐ and As‐mole fractions are varied. Four In‐mole fractions are studied and 0.07), and their emitted wavelengths cover the range . Both In‐ and the As‐mole fraction increment results in a red‐shifted wavelength. Doping is also investigated where the structures are exhibited five times increment of modal gain, and the wavelength is blue‐shifted under doping. A multi‐peak behaviour is exhibited by these structures, which is essential in applications for choosing the required wavelength. These results promise that these structures can work in UV, visible, and infrared (IR) wavelength ranges.