Fig. 4. (Color online) (a) The setup structure for utilizing the electroluminescence of colloidal quantum dots (b) Electroluminescence spectrum according to PMMA layer thickness. All samples received equal exposure to a voltage of 2.8 V. The thickness of the PMMA layer is 17 nm, 12 nm, 10.4 nm, and 0 nm from top to bottom. The left part(blue box) represents the background noise, and the middle part(red box) is the wavelength range in which the original field emission appears. It demonstrates that the background noise is low, and the intensity of the field emission is dominant when the PMMA layer is at 12 nm [Reprinted with permission from Ref.
38. Copyright 2017 Springer Nature].
