In the conventional liquid crystal display (LCD), light-shielding matrixes and polarizers are generally formed in two independent layers, as a result, not only the production cost is increased but also the display device is thickened.
Quantum dot materials have been used to manufacture a color filter (CF) substrate in an LCD device. Quantum dot is a semiconductor nanostructure for binding a conduction band electron, a valence band hole and an exciton in three spatial directions. The confinement can arise from electrostatic potential (generated by external electrodes, doping, strain, or impurities), interface of two different semiconductor materials (e.g., in self-assembled quantum dots), surface of semiconductors (e.g., semiconductor nanocrystals), or a combination thereof. Quantum dot is a nanoparticle formed by II-VI or III-V group elements. The particle diameter of the quantum dot is generally ranged from 1 to 10 nm. As electrons and holes are confined by quantum dots, continuous energy band structures become discrete energy band structures with molecular properties which can emit fluorescent light after excitation. Based on quantum effect, the quantum dot can be widely applied in the fields such as solar cells, luminescent devices and optical biomarkers.
In the display field, a white light-emitting diode (LED) backlight and conventional color filters (CFs) are generally matched with each other to form a color display light source which has the problems of low utilization rate, narrow color gamut of display, etc. When the quantum dots are adopted as CF materials, the display color gamut can be effectively improved.