High-Responsivity SWIR Alloy Photodetectors
Abstract
The SWIR light wavelength range is typically defined from 900 - 1700nm which is outside of the fairly minimal range humans can naturally view of visible light (350 - 700nm). SWIR photodetectors allow for the conversion of infrared light to visible light and have a plethora of applications in the modern world for visualization in fields such as surveillance, bioimaging, inspection, pollution, agriculture, automotive and many more. With SWIR photodetection being such a widely used technology, a demand for low-cost, ultra-high responsivity photodetectors sensitive to the SWIR wavelength range has surfaced. The most commonly utilized materials for SWIR detection lie in the III-V semiconductor family with InGaAs absorbers currently dominating the market. Although these materials spectral photosensitivity is high within the relevant wavelength range, they are costly to manufacture and have limited response times as well as poor silicon device integration. A viable alternative could be utilizing a metal-silicon schottky barrier interface to extend silicons detection range to the SWIR regime. This type of device utilizes a photoexcited metal to generate hot carriers as a means of converting incident photons into a measurable electrical charge. It is necessary that the metal have sufficient hot-carrier generation in the SWIR as well as a suitable carrier mean free path. Transition metals provide good absorption in the SWIR but have short carrier lifetimes due to their large electronic density of states near the Fermi level. Alloys can offer emergent properties not available with pure metals [1]. Through the alloying of certain transition metals, the resulting metals optical and electronic properties can be tuned via band hybridization to be a viable hot carrier generator. This work represents an ongoing effort in the goal to explore a new class of materials viable for ultra-fast current generation upon SWIR excitation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2021
- Accession Number
- AD1226790
Entities
People
- Henry W. Cain
Organizations
- Louisiana State University