A Large‐Area Patterned Hydrogen‐Bonded Organic Framework Electrochromic Film and Device

Abstract Fabrication of a patterned hydrogen‐bonded organic framework (HOF) films on a large scale is an extreme challenge. In this work, a large area HOF film (30 × 30 cm 2 ) is prepared via an efficient and low‐cost electrostatic spray deposition (ESD) approach on the un‐modified conductive substrates directly. Combining the ESD with a template method, variously patterned HOF films can be easily produced, including deer‐ and horse‐shaped films. The obtained films exhibit excellent electrochromic performance with multicolor change from yellow to green and violet, and two‐band regulation at 550 and 830 nm. Benefiting from the inherently present channels of HOF materials and the additional film porosity created by ESD, the PFC‐1 film could quickly change color (within 10 s). Furthermore, the large‐area patterned EC device is constructed based on the above film to prove practical potential application. The presented ESD method can be extended to other HOF materials; thus, this work paves a feasible path for constructing large‐area patterned HOF films for practical optoelectronic applications.