Grant: Idea to Innovation

Photodetectors which convert an incoming light signal to electric current or voltage are needed for an extremely diverse range of technologies from optical communication and environmental sensing to process control and materials characterization. One key performance metric for photodetectors is the spectral range of light that can be sensed. Broadband detectors that work over a wide range are more useful universally as different applications operate in different parts of the light spectrum. Other high-performance metrics include fast response speed, high detectivity for sensing of low light levels, room temperature operability which forgoes the need for cryogenic cooling, and device miniaturizability to allow for scalable production. The researchers have designed a novel photodetector heterostructure incorporating four different two-dimensional (2D) materials that is sensitive to light across a decade in energy from the mid infrared (IR) to deep ultraviolet (UV), or 0.3 to 5.0 eV, at room temperature. The peak specific detectivity reaches 3.4x10^9 Jones and the electrical bandwidth is 2.2 MHz, the fastest yet reported for detectors with deep UV to mid IR sensitivity. The active area can be made smaller than one square micron while unaffecting the broadband spectral response. This high-performance photodetector thus can be used ubiquitously across many different applications. For this technology, a US patent application was filed on Nov. 16, 2022 (No. 18/055,922), and a paper was published on Apr. 11, 2022 (Nano Lett. 2022, 22, 8, 3425-3432). This proposed project will be focused on elevating the performance and functionality of the photodetector even further in accordance with the needs of the market. It will: 1) characterize the improved characteristics of the current detector embodiment at low temperatures for research environments where cooling is not an issue; 2) expand the spectral range deeper into the IR by incorporating other 2D materials; and 3) develop detector arrays or area sensors using the most promising material heterostructures for multichannel imaging.