Vapour sensing properties of InP quantum dot luminescence

We investigated uncapped InP quantum dots grown epitaxially on InGaP buffer layer as an optically active element for chemical vapour detection. Near infrared luminescence has been studied as a function of the external environment. QD luminescence intensity changes rapidly and reversibly on exposure to methanol vapour while its spectral shape remains unchanged. For QDs about 45 nm average lateral size and 4–6 nm height, sensitivity to methanol vapour in the range 3.3 × 104–7.2 × 103 ppm has been demonstrated.