Flexible GaN for High Performance, Strainable Radio Frequency Devices (Postprint)

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 AlGaNGaN 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 sq cm V1 s1 and sheet carrier density above 1.07 10 expn 13 cm2. 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.