A research team at Soochow University in China has published a report which it says is the first demonstration of an LCD that combines gray scale and full-colour modulation without the need for colour filters or orientation layers.
The report, published in Applied Physics Review, says the project opens the door to new types of LCDs and the simplicity of the setup allows its potential integration in various other information and image display systems.
LCD technology uses electric voltage to manipulate molecules and control light, however, the organic molecules typically used in LCD technology often inhibit light sensitivity and control of color display. This has spurred various proposed alternatives that include orientation layers and colour filters, which can be complex and costly to manufacture.
The team has demonstrated an LCD device based on 2D inorganic nanosheets of α-zirconium phosphate, successfully realising a full colour display of single pixel liquid crystal without colour filters or orientation layers.
“This unusual achievement is possible because of the high Kerr coefficient of the inorganic nanosheet material, enabling first- and second-order interference,” said author Fengxia Geng. “The driving electric field is one to two orders of magnitude lower than that required for organic liquid crystals.”
The researchers developed a prototype device with resolution typical for a full colour light-emitting diode (LED) display screen --used in outdoor advertising and indoor event displays – which is able to be increased to 1200 pixels per inch. The simplified device design allows for each cell to be independently controlled, so that adding controllable circuits will more easily enable integration and enhance resolution.
“The prospect of stand-alone single pixel LCD devices that can achieve full colour modulation has been the holy grail in the field of display applications,” said Geng. “Considering the advantages of the simple design, the environmental friendliness of both the material and the fabrication process, and the greater stability of inorganic liquid crystals, we expect extensive application prospects.”