Fig. 1. Pixel arrangement of the conventional display with R/G/B side-by-side pixels and display in this work with color-tunable pixels.

Fig. 2. Architecture and physics of QLEDs with bias-tunable color. (a) Schematic of the device architecture. (b) Cross-sectional TEM image (I) and EDS compositional mapping images (II–V) of the fabricated QLEDs. (c) Energy band diagram of QLEDs. (d) HR-TEM images of R/G/B QD materials. Absorption spectra and normalized PL spectra of (e) R, (f) G, and (g) B QDs.

Fig. 3. Performance of monochromatic R/G/B QLEDs. (a) CIE 1931 color coordinates of monochromatic R/G/B QLEDs. (b) Voltage-dependent normalized EL spectral evolutions of monochromatic R/G/B QLEDs. (c) Photographs of monochromatic R/G/B QLEDs (emitting area of 0.5  cm×0.5  cm) at applied voltage. (d) Current density versus voltage, (e) luminance versus voltage, and (f) EQE versus current density for monochromatic R/G/B QLEDs.

Fig. 4. Demonstration of QLEDs with bias-tunable color. Normalized PL spectra of mixed R/G/B QDs used for the fabrication of full-color-tunable QLEDs with (a) formulation A, (b) formulation B, and (c) formulation C. Evolution of CIE 1931 color coordinates of (d) formulation A, B, and (e) formulation C-based full-color-tunable QLEDs with increasing bias voltages. Inset of (e): CCT can be adjusted from 1500 to 10,000 K, which well traces the blackbody trajectory. (f) Evolution of CIE 1976 color coordinates of formulation C-based full-color-tunable QLEDs with increasing bias voltages. The asterisk represents the white QLEDs in (e) and (f). (g) Evolution of as-recorded EL spectra of formulation C-based full-color-tunable QLEDs with increasing bias voltages. (h) EL contribution of R/G/B individual color to the entire EL spectra of formulation C-based full-color-tunable QLEDs at different bias voltages. (i) Photographs of formulation C-based full-color-tunable QLEDs (emitting area of 0.5  cm×0.5  cm) at different bias voltages.

Fig. 5. Performance of QLEDs with bias-tunable color. (a) Luminance and current density versus bias voltage for full-color-tunable QLEDs. (b) EQE versus bias voltage for full-color-tunable QLEDs. (c) Performance comparison of R/G/B QDs-mixed full-color QLEDs [1,2,4,20,20,28].

Table 1. Volume Ratios of Mixed R/G/B QDs Used for Fabrication of Full-Color-Tunable QLEDs

Table 2. Comparison of Full-Color QLEDs