We demonstrate the use of thin AlGaAs barrier layers in the quantum dots in a well heterostructure to enhance the quantum confinement of carriers in the excited energy level, while maintaining high escape probability. This is achieved by controlling the excited state energy between the confinement enhancing (CE) barriers and the continuum level. Responsivity of ∼0.1 A/W, detectivity of 6.5 × 1010cmHz1/2 W-1 (77 K, 0.6 V, 7.5 μm, f/2), and a factor of 10 improvement over a control sample without the CE barriers have been measured. The effect of changing the quantum well thickness and quantum dot size is also reported. © 2011 American Institute of Physics.