Photo-driven fin field-effect transistors

The integration between infrared detection and modern microelectronics offers unique opportunities for compact and high-resolution infrared imaging.However,silicon,the cornerstone of modern microelectronics,can only detect light within a limited wavelength range(<1100 nm)due to its bandgap of 1.12 eV,which restricts its utility in the infrared detection realm.Herein,a photo-driven fin field-effect transistor is presented,which breaks the spectral response constraint of conventional silicon detectors while achieving sensitive infrared detection.This device comprises a fin-shaped silicon channel for charge transport and a lead sulfide film for infrared light harvesting.The lead sulfide film wraps the silicon channel to form a“three-dimensional”infrared-sensitive gate,enabling the photovoltage generated at the lead sulfide-silicon junction to effectively modulate the channel conductance.At room temperature,this device realizes a broadband photodetection from visible(635 nm)to short-wave infrared regions(2700 nm),surpassing the working range of the regular indium gallium arsenide and germanium detectors.Furthermore,it exhibits low equivalent noise powers of 3.2×10^(-12) W·Hz^(-1/2) and 2.3×10^(-11) W·Hz^(-1/2) under 1550 nm and 2700 nm illumination,respectively.These results highlight the significant potential of photo-driven fin field-effect transistors in advancing uncooled silicon-based infrared detection.

Schottky infrared detectors with optically tunable barriers beyond the internal photoemission limit

Internal photoemission is a prominent branch of the photoelectric effect and has emerged as a viable method for detecting photons with energies below the semiconductor bandgap.This breakthrough has played a significant role in accelerating the development of infrared imaging in one chip with state-of-the-art silicon techniques.However,the performance of these Schottky infrared detectors is currently hindered by the limit of internal photoemission;specifically,a low Schottky barrier height is inevitable for the detection of low-energy infrared photons.Herein,a distinct paradigm of Schottky infrared detectors is proposed to overcome the internal photoemission limit by introducing an optically tunable barrier.This device uses an infrared absorbing material-sensitized Schottky diode,assisted by the highly adjustable Fermi level of graphene,which subtly decouples the photon energy from the Schottky barrier height.Correspondingly,a broadband photoresponse spanning from ultraviolet to mid-wave infrared is achieved,with a high specific detectivity of 9.83×1010 cm Hz1/2 W−1 at 2,700 nm and an excellent specific detectivity of 7.2×109 cm Hz1/2 W−1 at room temperature under blackbody radiation.These results address a key challenge in internal photoemission and hold great promise for the development of the Schottky infrared detector with high sensitivity and room temperature operation.