| Title |
Rapid Activation of Solution-Processed ZrOx Gate Dielectrics via Pulsed-UV Annealing for Pentacene OTFTs |
| Authors |
(Hyeonju Lee) ; (Bokyung Kim) ; (Taehui Kim) ; (Dongwook Kim) ; (Xue Zhang) ; (Jin-Hyuk Bae) ; (Youngjun Yun) ; (Sungkeun Baang) ; (Jaehoon Park) |
| DOI |
https://doi.org/10.3365/KJMM.2026.64.4.294 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Pentacene; Pulsed-UV annealing; Solution Process; Surface energy; ZrOx gate dielectric; Organic Thin-Film Transistor |
| Abstract |
High-permittivity zirconium oxide (ZrOx) gate dielectrics prepared by solution processing are
promising for low-temperature annealing processes that are incompatible with flexible substrates. In this
study, pulsed-ultraviolet (p-UV)-assisted thermal annealing was employed to rapidly activate ZrOx films at
200 oC within 5 min. These films were subsequently integrated into top-contact, bottom-gate pentacene thinfilm
transistors (TFTs). The p-UV-annealed ZrOx films retained high optical transmittance (>80%) and
exhibited optical band gaps of ~5.1 eV (hot plate, 200 oC/60 min) and ~5.2 eV (p-UV, 200 oC/5 min), thus
confirming that the accelerated process preserves the electronic structure. Water contact angles decreased
from 36.1o to 31.8o, corresponding to an increase in surface energy from 59.6 to 62.4 mJ/m2, consistent with
Fourier transform infrared spectroscopy evidence of reduced carbonaceous and carboxylic species. Pentacene
films grown on p-UV-annealed ZrOx exhibited larger grain sizes and smoother morphologies, with RMS
roughness of approximately 7.7 nm compared to 8.8 nm for the hot plate-annealed sample, which led to
improved inter-island connectivity. The device measured at VD = ? 4 V showed enhanced electrical
performance with p-UV treatment, with the field-effect mobility increasing from 3.10 to 4.13 cm2/V·s. The on/
off current ratio improved from 5.63 × 105 to 4.06 × 106, whereas the threshold voltage remained nearly
unchanged. These results demonstrate that p-UV-assisted annealing offers a fast, energy-efficient, and
substrate-compatible approach to prepare high-quality ZrOx gate dielectrics for high-performance pentacene
organic TFTs. |