Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, OH, 45433, USA.
Air Force Research Laboratory, Sensors Directorate, Wright-Patterson AFB, OH, 45433, USA.
Adv Mater. 2017 Dec;29(47). doi: 10.1002/adma.201701838. Epub 2017 Nov 2.
Flexible gallium nitride (GaN) thin films can enable future strainable and conformal devices for transmission of radio-frequency (RF) signals over large distances for more efficient wireless communication. For the first time, strainable high-frequency RF GaN devices are demonstrated, whose exceptional performance is enabled by epitaxial growth on 2D boron nitride for chemical-free transfer to a soft, flexible substrate. The AlGaN/GaN heterostructures transferred to flexible substrates are uniaxially strained up to 0.85% and reveal near state-of-the-art values for electrical performance, with electron mobility exceeding 2000 cm V s and sheet carrier density above 1.07 × 10 cm . The influence of strain on the RF performance of flexible GaN high-electron-mobility transistor (HEMT) devices is evaluated, demonstrating cutoff frequencies and maximum oscillation frequencies greater than 42 and 74 GHz, respectively, at up to 0.43% strain, representing a significant advancement toward conformal, highly integrated electronic materials for RF applications.
柔性氮化镓 (GaN) 薄膜可以实现未来的可拉伸和贴合设备，用于远距离传输射频 (RF) 信号，从而实现更高效的无线通信。首次展示了可拉伸的高频 RF GaN 器件，其优异的性能得益于在二维氮化硼上进行的外延生长，可实现无化学处理的转移到柔软、灵活的衬底上。转移到柔性衬底上的 AlGaN/GaN 异质结构可承受高达 0.85%的单轴应变，并展现出接近最新技术水平的电学性能，电子迁移率超过 2000 cm V s，面载流子密度高于 1.07×10 cm 。评估了应变对柔性 GaN 高电子迁移率晶体管 (HEMT) 器件的 RF 性能的影响，在高达 0.43%的应变下，分别展示了超过 42 和 74 GHz 的截止频率和最大振荡频率，这是朝着用于 RF 应用的贴合式、高度集成电子材料的重要进展。
