A 6-TFT Charge-Transfer Self-Compensating Pixel Circuit for Flexible Displays

Abstract

In this paper, a self-compensating 6 thin-film transistor (TFT) pixel circuit with special layout considerations has been proposed to mitigate the impact of the electrical instability of hydrogenated amorphous silicon TFTs as well as applied mechanical strain. The proposed pixel circuit has been fabricated onto flexible polyethylene naphthalate (PEN) substrate and the measurement results demonstrated less than ±3% variation of its output current after an accelerated 24-h stress test under flat, tensile strain, and compressive strain conditions. In addition, the proposed pixel circuit only required a pair of signals to operate, which reduced the complexity on external IC drivers.

Integration of GaN light-emitting diodes with a-Si:H thin-film transistors for flexible displays

“…Considerations such as higher thermal expansion coefficient mismatch and the thermal budget of the TFT process result in higher misalignment between the TFT layers. Consequently, the gate-to-source electrode overlap area of T 1 is increased resulting in a larger gate-source-contact overlap capacitance (C GS,1 ) and more charge-injection loss caused by the high-to-low transition of signal V 1 given by [18]:…”

Threshold-Voltage Extraction Methods for Atomically Deposited Disordered ZnO Thin-Film Transistors

“…Oxide semiconductors such as zinc oxide (ZnO), indium-gallium-zinc oxide (IGZO), and indium-zinc oxide (IZO) have been extensively investigated for their application in transparent electronics, the backplanes of large-area active-organic light-emitting-diode displays, and liquid crystal displays due to their high mobility, high transparency to visible light, and low processing temperatures [1][2][3][4]. However, oxide-semiconductor-based thin-film transistors (TFTs) suffer from severe threshold shifts during operation; therefore, compensation circuits are generally incorporated in their applications [5,6]. The threshold voltage (V th ) of TFTs is a gate voltage required to turn the devices on and is estimated using several methods, including a commonly used linear fitting method [7,8], a field-effect mobility derivation method [9], and a constant-current method [10].…”

Subgap states in aluminium- and hydrogen-doped zinc-oxide thin-film transistors

“…[1][2][3][4] However, oxide-semiconductor-based thin-film transistors (TFTs) suffer from severe threshold shifts and operational instabilities. 5,6 Although these instabilities can be mitigated by incorporating compensation circuits in their applications, 7 fundamental stability issues remain. For an in-depth understanding of the issues, several studies have been carried out, such as exploring the energy-state distributions using hard X-ray photoelectron spectroscopy, 8 characterization of the defect states from first principles, [9][10][11][12] and experiments utilizing photoexcitation and electrical methods.…”