Choi Junhwan, Lee Chungryeol, Kang Juyeon, Lee Changhyeon, Lee Seung Min, Oh Jungyeop, Choi Sung-Yool, Im Sung Gap
Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
School of Electrical Engineering, Graphene/2D Materials Research Center, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
Small. 2022 Sep;18(39):e2203165. doi: 10.1002/smll.202203165. Epub 2022 Aug 26.
Organic/inorganic hybrid materials are utilized extensively as gate dielectric layers in organic thin-film transistors (OTFTs). However, inherently low dielectric constant of organic materials and lack of a reliable deposition process for organic layers hamper the broad application of hybrid dielectric materials. Here, a universal strategy to synthesize high-k hybrid dielectric materials by incorporating a high-k polymer layer on top of various inorganic layers generated by different fabrication methods, including AlO and HfO , is presented. Those hybrid dielectrics commonly exhibit high capacitance (>300 nF·cm ) as well as excellent insulating properties. A vapor-phase deposition method is employed for precise control of the polymer film thickness. The ultralow-voltage (<3 V) OTFTs are demonstrated based on the hybrid dielectric layer with 100% yield and uniform electrical characteristics. Moreover, the exceptionally high stability of OTFTs for long-term operation (current change less than 5% even under 30 h of voltage stress at 2.0 MV·cm ) is achieved. The hybrid dielectric is fully compatible with various substrates, which allows for the demonstration of intrinsically flexible OTFTs on the plastic substrate. It is believed that this approach for fabricating hybrid dielectrics by introducing the high-k organic material can be a promising strategy for future low-power, flexible electronics.
有机/无机杂化材料被广泛用作有机薄膜晶体管(OTFT)中的栅极介电层。然而,有机材料固有的低介电常数以及缺乏可靠的有机层沉积工艺阻碍了杂化介电材料的广泛应用。在此,提出了一种通用策略,即通过在由不同制造方法(包括AlO和HfO)生成的各种无机层顶部并入高k聚合物层来合成高k杂化介电材料。这些杂化电介质通常表现出高电容(>300 nF·cm)以及优异的绝缘性能。采用气相沉积法精确控制聚合物膜厚度。基于具有100%良率和均匀电学特性的杂化介电层展示了超低压(<3 V)OTFT。此外,实现了OTFT在长期运行中的极高稳定性(即使在2.0 MV·cm的电压应力下30小时,电流变化小于5%)。该杂化电介质与各种衬底完全兼容,这使得在塑料衬底上展示本征柔性OTFT成为可能。据信,通过引入高k有机材料来制造杂化电介质的这种方法对于未来的低功耗、柔性电子学可能是一种有前景的策略。