company news about Comparison between TFT LCD and OLED display

Currently, TFT-LCD panels that have matured in industrial development require backlighting due to the fact that liquid crystal materials themselves do not emit light. OLED is an organic light-emitting diode that can self emit without the need for a backlight. By controlling the current level through a TFT substrate, the brightness of the RGB organic film layer can be controlled, thereby blending the desired color. The difference in luminescence principles leads to the difference in device structures between the two, resulting in different characteristics. OLED has the advantages of being lightweight, high contrast, high brightness, low energy consumption, and wide viewing angle, and its response time is only one thousandth of that of LCD. Due to the fact that the light-emitting devices of AMOLED are solid-state OLEDs, and their display components are all solid-state, they can be easily made into flexible displays. Flexibility makes OLED applications not only limited to traditional 3C products, but also applicable in wearable devices, car displays, household appliances, and virtual reality (VR) industries. However, due to its drift or spatial mismatch, uneven display, and instability under long-term electrical stress, there are still technical challenges in its application in large-sized tablets and televisions.

OLED is a phenomenon of self luminescence caused by carrier injection and recombination. It uses a very thin organic material coating and a glass substrate. Its principle is to use ITO transparent electrodes and metal electrodes as the cathode and anode of the device, respectively. Under a certain voltage drive, electrons and holes are injected from the cathode and anode into the electron and hole transport layers, respectively. Electrons and holes migrate through the electron and hole transport layers to the luminescent layer, and meet in the luminescent layer to form excitons and excite the luminescent molecules, The latter emits visible light through radiation.

There are three main methods for OLED full-color conversion: RGB three color arrangement luminescence method, white light OLED+color filter film (CF) method, and blue light+color change layer (CCF) method. The most commonly used method at present is the RGB three color arrangement luminescence method, which uses independent red, blue, and green luminescent materials for arrangement luminescence, with high luminous efficiency. The production process of white light+CF structure is simple, which is a relatively economical method for OLED coloring. However, due to the presence of CF film, its luminous efficiency is relatively low. The light color conversion method of blue light+CCF has low luminous efficiency, and the development of color converters is difficult, so it has not yet entered the production stage.

The TFT-LCD panel structure can be seen as two glass substrates sandwiched between a layer of liquid crystal. The upper glass substrate is combined with a color filter, while the lower glass has transistors embedded in it (TFT Array). The current passing through the transistor generates an electric field change, causing the liquid crystal molecules to deflect, thereby changing the polarization of the light, and then using a polarizer to determine the brightness state of the pixel. In addition, the upper layer of glass is fitted with a color filter, forming each pixel containing three colors: red, blue, and green. These pixels emitting red, blue, and green colors form the image image on the panel. TFT-LCD technology has a high level of maturity and is currently one of the mainstream technologies for semiconductor displays. AMOLED, as a new technology for semiconductor display, has strong advantages in optical performance, electronic performance, integration function, and appearance, representing a new development direction of semiconductor display technology.

TFT-LCD panels and OLED panels have different choices of display materials in their respective manufacturing processes. LCD terminal materials and OLED terminal materials are the main manufacturing materials for both types of panels. Due to the different characteristics of the two display materials, the two display panels also exhibit their own product characteristics. In terms of technology, OLED generally has a lower yield and higher cost than TFT-LCD. At present, it is suitable for small and medium-sized display screens, while large-sized screens are just starting out.