A room-temperature mid-infrared photodetector for on-chip molecular vibrational spectroscopy
Abstract
Infrared (IR) photodetection is of major scientific and technical interest since virtually all molecules exhibit characteristic vibrational modes in the mid-infrared region of the spectrum, giving rise to molecular spectroscopy and chemical imaging in this wavelength range. High-resolution IR spectroscopies, such as Fourier Transform IR spectroscopy, typically require large, bulky optical measurement systems and expensive photodetector components. Here, we present a high-responsivity photodetector for the mid-IR spectral region which operates at room temperature. Fabricated from silicon and aluminum, the photodetection mechanism is based on free carrier absorption, giving rise to a photoresponse rivalling commercially available cooled IR photodetectors. We demonstrate that infrared spectra of molecules deposited on this detector can be obtained by a direct electrical read-out. This work could pave the way for simple, fully integrated chemical sensors and other applications, such as chemical imaging, which would benefit from the combination of mid-IR detection, room-temperature operation, and ultracompact portability.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 03, 2018
- Source ID
- 10.1063/1.5045663
Entities
People
- Benjamin Cerjan
- Bob Zheng
- Emilie Ringe
- Hangqi Zhao
- Naomi J. Halas
- Peter Nordlander
- Sadegh Yazdi
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- Defense Threat Reduction Agency
- National Science Foundation
- Rice University
- Robert A. Welch Foundation