Room-temperature oxygen sensitization in highly textured, nanocrystalline PbTe films: A mechanistic study

• Main Authors: Wang, Jianfei (Contributor), Hu, Juejun (Contributor), Becla, Piotr (Contributor), Kimerling, Lionel C. (Contributor), Agarwal, Anuradha Murthy (Contributor)
• Other Authors: MIT Materials Research Laboratory (Contributor), Massachusetts Institute of Technology. Department of Materials Science and Engineering (Contributor), Massachusetts Institute of Technology. Microphotonics Center (Contributor)
• Format: Article
• Language: English
• Published: American Institute of Physics (AIP), 2013-07-30T18:34:43Z.
• Subjects: Article
• Online Access: Get fulltext

In this paper, we report large mid-wave infrared photoconductivity in highly textured, nanocrystalline PbTe films thermally evaporated on Si at room temperature. Responsivity as high as 25 V/W is measured at the 3.5 μm wavelength. The large photoconductivity is attributed to the oxygen incorporation in the films by diffusion. Carrier concentration as low as 10[superscript 17] cm[superscript −3] is identified to be the consequence of Fermi level pinning induced by the diffused oxygen. The successful demonstration of IR-sensitive PbTe films without the need for high-temperature processing presents an important step toward monolithic integration of mid-wave PbTe infrared detectors on Si read-out integrated circuits (ROICs).