Rapid photo-assisted activation and enhancement of solution-processed InZnO thin-film transistors

Abstract

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.

Performance and Stability Enhancement of Fully Solution-Processed a-InZnO Thin-Film Transistors via Argon Plasma Treatment

“…We used an IZO solution which was provided by Nissan Chemical Corporation, Japan. Further details of the IZO precursor can be found in our previous reports. − The IZO precursor solution, with 77 and 23 wt % ratio between In and Zn, was deposited on the cleaned substrate using spin-coating technique and then subjected to a two-step baking process at 150 and 300 °C for 5 min each. The a-IZO deposition step was repeated five times until a nominal thickness of 70 nm was reached.…”

Continuous-Wave Green Laser Activation of Transparent InZnO Electrodes for Fully Solution-Processed Oxide Thin-Film Transistors

“…The most common strategy is performing a thermal annealing step > 400 °C for several hours to achieve acceptable device performance. ,, Attempts to lower the induced temperature on the device involve the use of microwave annealing, , high-pressure annealing, , and photochemical activation. − In particular, photoactivation is a sustainable technique wherein the energetic photons from the light source aid in the decomposition of precursors and the subsequent densification of metal oxide. , Several reports have demonstrated UV irradiation to be effective in accelerating precursor decomposition and subsequent metal-oxide formation. , On the other hand, laser irradiation is another strategy that is preferred over conventional thermal treatment in terms of addressing issues such as high thermal budget, long processing times, and incompatibility with heat-sensitive substrates, which leads to mechanical failure . Laser processing primarily works by generating high energy in a confined area using a focused laser to induce photothermal effects at a target location. − This localization of the thermal effect makes it possible to produce minimal to zero interactions with the underlying layers, substrate, or even adjacent structures, making it interesting in diverse materials processing, which requires selective annealing, − patterning, − crystal growth, , and ablation. , Laser irradiation has been used to tailor the characteristics of metal oxide films and nanostructures for diverse applications such as dielectric materials, , solar cells, ferroelectric oxide thin films, transparent conductors, ,− and TFTs. ,,,,− Previously, we demonstrated the use of excimer laser and UV irradiation to induce structural modification in an a-IZO film . Combining excimer laser irradiation with UV irradiation has been shown to be critical for achieving the superior characteristics of fully solution-processed a-IZO TFTs.…”

Application of Laser Treatment in MOS-TFT Active Layer Prepared by Solution Method

“…Laser treatment can effectively treat precursor films or nanoparticles through high-energy radiation and absorption of high-energy photons. By adjusting the laser processing parameters, such as laser intensity, pulse width and scanning speed, the energy input into the film can be accurately controlled to achieve the desired thermal effect [38][39][40][41][42][43]. In addition, the heating and cooling rate of laser treatment (>10 6 • C s −1 ) is several orders of magnitude higher than that of conventional heat treatment and rapid thermal treatment, so that the thin films can be processed quickly with minimal energy loss [44].…”

“…In addition, the heating and cooling rate of laser treatment (>10 6 • C s −1 ) is several orders of magnitude higher than that of conventional heat treatment and rapid thermal treatment, so that the thin films can be processed quickly with minimal energy loss [44]. Laser treatment is a top-down treatment technology and the treatment position can be accurately controlled, so the treatment area can be limited to a specific range of in-plane and thickness direction, and the thin films and nanostructures can be selectively treated to improve the properties of thin films and MOS-TFT without affecting the substrate and adjacent materials [43,[45][46][47]. Common laser treatment equipment is shown in Figure 3 [48].…”