Gate driver with low‐temperature polycrystalline silicon and oxide thin‐film‐transistor circuits for low power consumption and narrow bezel AMOLED displays

Abstract

We propose a novel gate driver circuit using low-temperature polycrystalline silicon and oxide (LTPO) thin-film transistors (TFTs). The proposed circuit consists of only six TFTs, four p-type LTPS, and two n-type a-IGZO TFTs, without capacitor. The proposed circuit operates well when oxide TFTs have threshold voltage (V TH ) of À7.5 V, which is very depletion mode. Without bootstrapping, low gate bias stress occurs on TFTs in the proposed circuit. With dual gate (DG) structure of oxide TFTs, the stability of the proposed circuit is improved. In addition, by utilizing extremely low off-state current of oxide TFTs, ultra-low power consumption can be achieved. The total power consumption of the proposed gate driver is less than 100 mW under a-IGZO TFT's V TH of À6 V at 120 Hz 4k (3,840 Â 2,160) resolution display. The fabricated circuit works perfectly at a pulse width of 1 μs equivalent to operating speed of 500 kHz. The proposed circuit can be applied to ultra-high definition (UHD) and narrow bezel AMOLED display. K E Y W O R D Sdepletion mode, gate driver, low-temperature polycrystalline silicon and oxide (LTPO), power consumption, reliability, thin-film transistor (TFT)

Light Effect on Amorphous Tin Oxide Thin‐Film Transistors

“…One of the purposes to study thin-film transistor (TFTs) is to implement them in large-area electronics, like active matrix organic light-emitting diodes (AMOLEDs). [1,2] Development of materials to improve the performances of TFTs has been one way. For that reason, amorphous indium gallium zinc oxide (a-IGZO) and other oxide semiconductors have been under the spotlight for more than 15 years.…”

“…[22] ITZO TFTs with mobility of 27.7 cm 2 Vs À1 were also achieved. [23] Not only does ALD offer high performance devices, but also the process allows to build TFT in which the channel can be made of multiple layers, [24] like IGZO made of layers of In 2 O 3 /Ga 2 O 3 /ZnO and can lead to mobility over 100 cm 2 Vs À1 with careful plasma treatment on the Ga 2 O 3 layer. [25] High-k dielectrics, like Al 2 O 3 deposited by ALD, can lead to mobilities of 23.3 cm 2 Vs À1 .…”

Integrated Water-Level Sensor Using Thin-Film Transistor Technology

“…In addition to their widespread use in displays, TFTs have found diverse applications in sensors, circuits, and radio frequency identification (RFID) systems. − TFTs play a critical role in high-performance displays by serving as scan drivers and pixel circuits for the OLED panels. These TFTs are commonly integrated with TFTs on a glass substrate, forming an essential component of the display system. , Furthermore, TFTs have demonstrated their versatility in the development of diverse sensor types, including photo, fingerprint, temperature, gas, infrared (IR), and ultraviolet (UV) sensors. This is attributable to their compact form factor, energy efficiency, and scalability, making TFTs an ideal choice for sensor applications requiring miniaturization, low power consumption, and adaptability. − Consequently, the significance of TFTs is steadily rising in the realm of emerging technologies, notably, flexible electronics, medical devices, and wearable technology.…”

P‐2: Narrow Bezel Gate Driver Generating Positive Pulse for AMOLED Display Using LTPO Technology with Depletion Mode Oxide TFTs

“…Thus, GOAs composed of LTPS TFTs have limitation to reduce the bezel area. We reported the gate drivers with LTPO TFTs only for p-type LTPS switching TFTs in LTPO pixel circuits [8][9][10][11]. In this work, we propose novel gate driver generating positive pulse for n-type oxide switching TFTs in AMOLED pixel circuits using LTPO technology.…”