Room temperature terahertz detector based on single silicon nanowire junctionless transistor with high detectivity

Abstract

In this work, the n-type single silicon nanowire (NW) based junctionless field-effect transistor (FET) is demonstrated as an efficient terahertz (THz) detector. For the effective coupling of the THz radiations with NW junctionless FET, the lobes of the rounded bow-tie antenna are connected to the gate and source terminals of the device. The antenna design is optimized with proper impedance matching conditions to achieve maximum power transfer between antenna and detector. The simulated antenna resonates at 0.43 THz frequency with 19 GHz bandwidth. Further simulations have been done on Lumerical finite difference time domain software to analyze the electric field distribution profile. To investigate the optical response of this optimized antenna design, an array of the simulated antenna has been fabricated and its transmission spectra are measured. Finally, the simulated antenna has been integrated with the n-type NW junctionless transistor. A maximum responsivity of 468 V W−1 at 0.425 THz frequency and noise-equivalent-power of ∼ 10−9W/Hz1/2 is obtained at room temperature. The complementary metal-oxide-semiconductor’s compatibility, ease of integration on chips, possibility to realize multiple pixel arrays, andscalability to higher frequencies, make this device promising for THz electronics.