Pyrolysis of Acoustic‐Mixed SU8/CNTs for High Field Emission Performance Cold Cathode

This study addresses the difficulty of removing binders from conventional carbon nanotube (CNT)‐based pastes and the poor adhesion between CNT cold cathode and metal substrates. SU8 photoresist was introduced as a binder—which pyrolyzes into glassy carbon after annealing, eliminating the need for removal while forming conductive pathways between CNTs. Furthermore, this study employed acoustic resonance dispersion technology to successfully disperse CNTs in SU8 photoresist at a vibration frequency of 80 Hz and a dispersion time of 90 min. The CNTs/SU8‐based paste was printed onto a Kovar substrate using a screen‐printing process. Subsequently, high‐temperature annealing at 900 °C was performed to pyrolyze the SU8 photoresist into glassy carbon. Thereby fabricating a glassy carbon/CNTs composite cathode, significantly improving adhesion and emission stability. The 8 × 8 array patterned cathode exhibited a turn‐on field of 1.1 V/μm, an emission current density of 12.7 mA/cm ² at 3  V/μm, a field enhancement factor of 7853.7, and stable operation with only 7.4% current fluctuation over 10 h. This work provides an effective and mass production process for high‐adhesion, high‐performance CNT cold cathodes, offering a viable pathway for their large‐scale industrial application.