Universally Applicable Three-Dimensional Photo-Crosslinkers for All-Photopatterned Electronics

Fabrication of electronic components at high resolution remains a challenging task for organic electronic devices fabricated entirely through a series of solution processes. We report the all-solution processing of highly integrated arrays of organic thin-film transistors (OTFTs) and logic gates. This processing is performed using newly developed multi-bridge photo-crosslinkers containing 4 or 6 photo-crosslinkable units. Under UV, photo-crosslinkers mixed within solution-processable electronic materials generate a three-dimensional (3D) network of the given host electronic materials. We note that our photo-crosslinkers can produce the 3D network state efficiently even at an unprecedentedly small loading (only 1 or lower wt%), which, in turn, enables preservation of the intrinsic electrical properties of the photo-crosslinked material. Moreover, the crosslinking of electronic component layers allows not only micropatterning of the layers at high resolution (&lt; 5 µm) but also stacking of a given electronic component layer on top of the other layers.^[1,2] Furthermore, our efficient photo-crosslinkers enable to produce an ultrathin polymer gate dielectric, the application of which results in excellent hole and electron mobilities of 12.4 and 10.1 cm²V^-1s^-1, respectively, from <i>p</i>- and <i>n</i>-type OTFTs operated at &lt; 3 V.^[3] These works demonstrate that the use of photo-crosslinkers paves a new avenue to fabricate future electronic devices.<br/><br/><b>References</b><br/>[1] Kim, M. J.^†; Lee, M.^†; Min, H.; Kim, S.; Yang, J.; Kweon, H.; Lee, W.; Kim, D. H.; Choi, J.-H.; Ryu, D. Y.; Kang, M. S.*; Kim, B.*; Cho, J. H.* "Universal Three-Dimensional Crosslinker for All-Photopatterned Electronics" <b><i>Nat. Commun.</i></b> <b>2020</b>, <i>11</i>, 1520.<br/>[2] Jang, W.^†; Lee, M^†. ; Kweon, H.; Park, H. W.; Yang, J.; Kim, S.; Jo, H.; Lee, C.; Cho, J. H.; Kwak, K.; Kim, D. H.; Kim, B.*; Kang, M. S.* "Tetrabranched Photo-Crosslinker Enables Micrometer-Scale Patterning of Light-Emitting Super Yellow for High-Resolution OLEDs" <b><i>ACS Photonics</i></b> <b>2021</b>, <i>8</i>, 2519-2528.<br/>[3] Lee, M.^†; Cho, B.^†; Ahn, P.; Choi, Y. Y.; Heo, Y.; Kim, J.; Min, J. H.; Shin, T. J.; Kim, K.; Choi, H.; Kweon, H.; Ho, D. H.; Yoon, J.; Kim, H.; Lee, E.; Kim, D. H.; Kwak, K.; Kang, M. S.; Cho, J. H.*; Kim, B.* “Low Voltage Organic Transistors with Carrier Mobilities over 10 cm²V^-2s^-1 Using Six-Branched Organic Azide” <b><i>Chem. Mater.</i></b> <b>2022</b>, <b><i>ASAP</i></b>.