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Title: Nitrogen-related intermediate band in P-rich GaN xP yAs 1-x-y alloys

The electronic band structure of phosphorus-rich GaN xP yAs 1-x-y alloys (x ~ 0.025 and y ≥ 0.6) is studied experimentally using optical absorption, photomodulated transmission, contactless electroreflectance, and photoluminescence. Here, it is shown that incorporation of a few percent of N atoms has a drastic effect on the electronic structure of the alloys. The change of the electronic band structure is very well described by the band anticrossing (BAC) model in which localized nitrogen states interact with the extended states of the conduction band of GaAsP host. The BAC interaction results in the formation of a narrow intermediate band (E - band in BAC model) with the minimum at the Γ point of the Brillouin zone resulting in a change of the nature of the fundamental band gap from indirect to direct. The splitting of the conduction band by the BAC interaction is further confirmed by a direct observation of the optical transitions to the E + band using contactless electroreflectance spectroscopy.
Authors:
 [1] ;  [1] ; ORCiD logo [1] ;  [2] ;  [2] ;  [2] ;  [2] ;  [3] ;  [1]
  1. Wroclaw Univ. of Science and Technology, Wroclaw (Poland). Faculty of Fundamental Problems of Technology
  2. Univ. of Rennes, Rennes(France). FOTON Lab.
  3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division
Publication Date:
Grant/Contract Number:
AC02-05CH11231; DI2013006143
Type:
Accepted Manuscript
Journal Name:
Scientific Reports
Additional Journal Information:
Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 2045-2322
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); National Science Centre Poland
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; Electronic properties and materials; Semiconductors
OSTI Identifier:
1419449