Ferroelectric Localized Field Enhanced Cadmium Sulfide Nanoribbon Photodetectors

A high-performance ferroelectric side-gated cadmium sulfide nanoribbon (CdS NR) photodetector was fabricated at room temperature. By manipulating the local field induced by ferroelectric polarization, the intrinsic carriers in the CdS NR channel are effectively depleted by the intense electrostatic field, significantly reducing the dark current. The lower dark current also leads to very low noise current power of 4.3 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−28</sup> A<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, with noise current as low as 2.1 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−14</sup> A. Under illumination at a wavelength of 520 nm (0.03 mW/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>), the responsivity of the device is 6.3 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> A/W, the external quantum efficiency is 1.5 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup>%, and the specific detectivity is 3.5 × 10<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> Jones. The response times are 36 ms and 61 ms, respectively. The results indicate that the ferroelectric polarization localized field enhancement mechanism is promising for designing high-performance and low-power nanoribbon photodetectors.