The realization of next-generation flexible electronics involves the successful integration of functional solutionprocessed materials using simple and low-temperature fabrication techniques that are applicable to heat-sensitive substrates. Although there are numerous studies on the single solutionprocessed layer in an oxide thin-film transistor (TFT) structure, integrating all solution-based layers remains challenging. Here, fully solution-processed amorphous InZnO (a-IZO) TFTs were demonstrated utilizing the solution-based channel, gate insulator, and electrodes with a maximum fabrication temperature of 300 °C. Particularly, a single layer of a-IZO was used as both the channel and the source/drain electrode layer by selectively tuning the role of a-IZO as a semiconductor or a conductor through photoassisted treatments. By employing a self-aligned TFT structure, the a-IZO electrodes were functionalized by UV irradiation and excimer laser annealing (ELA). The fully solution-processed a-IZO TFTs exhibited high performance with an average mobility of up to 38 cm 2 V −1 s −1 , which surpasses those of previously reported approaches for fully solution-processed oxide TFTs. Moreover, the overall device performance, including a subthreshold swing of 225 mV dec −1 and an on-voltage of −0.4 V, is comparable to those of vacuum-processed oxide TFTs. In-depth analyses suggest that the successful functionalization of the a-IZO semiconductor into conductive electrodes is due to oxygen vacancy generation after UV treatment and subsequent crystallization and densification of the irradiated a-IZO areas after ELA. The demonstration of simple low-temperature photofunctionalization of solution-based oxide materials can be applied to 3D printing and can advance the high-throughput display manufacturing such as roll-to-roll processing.

We demonstrated gate insulators (GI) fabricated by solution process with the aim of replacing traditional vacuum processed GI. We selected solution siloxane-based material due to its extremely high thermal resistance, excellent transparency, flexibility, and simple cost-effective fabrication. We made top gate TFT by depositing a siloxane gate insulator through spin-coating technique on a-IGZO. For comparison, we measured a conventional a-IGZO TFT using SiO2 as a GI for a reference. The TFTs with siloxane GI showed extremely high mobility (µ= 22±3 cm2·V-1·s-1), ultra-smooth interface (no hysteresis), and including other suitable electrical characteristics that are promising to enable the possibility to fabricate high performance all-solution processed devices in the future.

We report the development of high performance all‐solution processed oxide thin‐film transistors (TFT) via selective photo‐induced semiconductor‐to‐conductor transformation of a‐InZnO. This simple method enables TFT fabrication through deposition of three main layers without additional source, drain, and gate deposition. This method has a large potential for high throughput roll‐to‐roll fabrication.

We demonstrate the rapid (<100 ns) activation and enhancement of solution-processed InZnO thin-film transistors (TFT) via a photo-assisted process: excimer laser annealing (ELA). A single shot is sufficient to enhance mobility from 0.19 cm2 V−1 s−1 to 3.91 cm2 V−1 s−1. Through multiphysics simulation, we confirmed that the process is instantaneous (<100 ns) and induces low substrate temperature suitable for flexible substrates. Analysis of optical properties, elemental concentration, and bonding changes after ELA revealed an improved metal-oxide formation and effective reduction of precursor-related impurities and oxygen vacancy traps. These demonstrate ELA’s potential for high-throughput fabrication of solution-processed devices for large-area, transparent, and flexible electronics.

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