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Title: Ultrasensitive photodetectors exploiting electrostatic trapping and percolation transport

The sensitivity of semiconductor photodetectors is limited by photocarrier recombination during the carrier transport process. We developed a new photoactive material that reduces recombination by physically separating hole and electron charge carriers. This material has a specific detectivity (the ability to detect small signals) of 5 × 10 17 Jones, the highest reported in visible and infrared detectors at room temperature, and 4-5 orders of magnitude higher than that of commercial single-crystal silicon detectors. The material was fabricated by sintering chloride-capped CdTe nanocrystals into polycrystalline films, where Cl selectively segregates into grain boundaries acting as n-type dopants. Photogenerated electrons concentrate in and percolate along the grain boundaries - a network of energy valleys, while holes are confined in the grain interiors. This electrostatic field-assisted carrier separation and percolation mechanism enables an unprecedented photoconductive gain of 10 10 e - per photon, and allows for effective control of the device response speed by active carrier quenching.
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7]
  1. Univ. of California, Berkeley, CA (United States). Applied Science and Technology Graduate Program; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Division
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering; Kavli NanoScience Inst., Berkeley, CA (United States)
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Division; Kavli Energy NanoScience Inst., Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States). Dept. of Chemistry
  4. Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Engineering
  5. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Molecular Foundry
  6. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Division; Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Engineering
  7. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Science Division; Kavli Energy NanoScience Inst., Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States). Dept. of Chemistry, Dept. of Materials Science and Engineering
Publication Date:
Grant/Contract Number:
AC02-05CH11231; AC02-05CH11232
Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 7; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; electronic devices; nanoscale materials
OSTI Identifier:
1379403

Zhang, Yingjie, Hellebusch, Daniel J., Bronstein, Noah D., Ko, Changhyun, Ogletree, D. Frank, Salmeron, Miquel, and Alivisatos, A. Paul. Ultrasensitive photodetectors exploiting electrostatic trapping and percolation transport. United States: N. p., Web. doi:10.1038/ncomms11924.
Zhang, Yingjie, Hellebusch, Daniel J., Bronstein, Noah D., Ko, Changhyun, Ogletree, D. Frank, Salmeron, Miquel, & Alivisatos, A. Paul. Ultrasensitive photodetectors exploiting electrostatic trapping and percolation transport. United States. doi:10.1038/ncomms11924.
Zhang, Yingjie, Hellebusch, Daniel J., Bronstein, Noah D., Ko, Changhyun, Ogletree, D. Frank, Salmeron, Miquel, and Alivisatos, A. Paul. 2016. "Ultrasensitive photodetectors exploiting electrostatic trapping and percolation transport". United States. doi:10.1038/ncomms11924. https://www.osti.gov/servlets/purl/1379403.
@article{osti_1379403,
title = {Ultrasensitive photodetectors exploiting electrostatic trapping and percolation transport},
author = {Zhang, Yingjie and Hellebusch, Daniel J. and Bronstein, Noah D. and Ko, Changhyun and Ogletree, D. Frank and Salmeron, Miquel and Alivisatos, A. Paul},
abstractNote = {The sensitivity of semiconductor photodetectors is limited by photocarrier recombination during the carrier transport process. We developed a new photoactive material that reduces recombination by physically separating hole and electron charge carriers. This material has a specific detectivity (the ability to detect small signals) of 5 × 10 17 Jones, the highest reported in visible and infrared detectors at room temperature, and 4-5 orders of magnitude higher than that of commercial single-crystal silicon detectors. The material was fabricated by sintering chloride-capped CdTe nanocrystals into polycrystalline films, where Cl selectively segregates into grain boundaries acting as n-type dopants. Photogenerated electrons concentrate in and percolate along the grain boundaries - a network of energy valleys, while holes are confined in the grain interiors. This electrostatic field-assisted carrier separation and percolation mechanism enables an unprecedented photoconductive gain of 10 10 e - per photon, and allows for effective control of the device response speed by active carrier quenching.},
doi = {10.1038/ncomms11924},
journal = {Nature Communications},
number = ,
volume = 7,
place = {United States},
year = {2016},
month = {6}
}