Facile interfacial defect healing in solution-processed In-Ga-Zn-O thin film transistor through rapid intense pulsed light annealing

Abstract

We introduce intense pulsed light (IPL) annealing as a versatile and cost-effective interface treatment approach for solution-processed In-Ga-Zn-O thin film transistor, focusing on its potential to improve its operational stability. We fabricate solution-processed IGZO-based thin film transistors (IGZO-TFTs) and systematically investigate the dependence of IPL shot numbers on key parameters that dictate the electrical characteristics of the devices. Under identical positive bias stress (PBS) conditions, we compare the operational stability of IGZO-TFTs treated with IPL annealing during ∼5 min to those subjected to conventional high-temperature thermal processes during 2 h, and reveal that IPL-annealed IGZO-TFTs exhibit superior stability as well as significantly suppressed threshold voltage shifts by ∼22 % (from 3.31 to 2.58 V). To gain deeper insights, we employ photo-excited charge collection spectroscopy analysis, which provides quantitative evidence of the rapid recovery of oxygen vacancies and hydrogen-related interfacial defect states (located at 2.1 ∼ 2.5 eV and near 2.79 eV below conduction band minimum) affecting operational device stability. Our findings underscore the technical advantages of IPL annealing over time-consuming thermal processes, positioning it as a promising method for optimizing IGZO-TFT performance. © 2023