Charge Transport Mechanisms in a Pb2P2Se6 Semiconductor

Svetlana S. Kostina, Micah P. Hanson, Peng L. Wang, John A. Peters, David A. Valverde-Chávez, Pice Chen, David G. Cooke, Mercouri G Kanatzidis, Bruce W. Wessels

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Charge transport in semi-insulating Pb2P2Se6 single crystals was investigated. The dark current was dominated by the ionization of deep-level defects within the gap of the material, with activation energies between 0.6 and 0.8 eV. A model for charge transport was developed where a continuum of these midgap defect levels determined the conductivity of Pb2P2Se6. Current-voltage characteristics in Pb2P2Se6 single crystals showed nonlinear behavior at high voltages. The nonlinear characteristics are attributed to competing Poole-Frenkel emission and phonon-assisted tunneling processes, such that at lower fields the former effect dominates, while at higher electric fields the latter mechanism emerges. Calculated tunneling times in the 250-500 fs range indicate that the deep traps promote weak electron-phonon coupling and that the tunneling involves deep defect levels. Transient multi-terahertz spectroscopy and temperature-dependent photoconductivity measurements reveal signatures of dispersive transport and low mobility on the order of 10 cm2/(V s), consistent with a disordered potential energy landscape in Pb2P2Se6. Photoresponse in these crystals is therefore limited by a distribution of trapping and recombination sites within the band gap.

Original languageEnglish
Pages (from-to)1877-1887
Number of pages11
JournalACS Photonics
Volume3
Issue number10
DOIs
Publication statusPublished - Oct 19 2016

Fingerprint

Phonons
Semiconductors
Terahertz Spectroscopy
Charge transfer
Semiconductor materials
Defects
defects
Single crystals
Terahertz spectroscopy
Genetic Recombination
Dark currents
single crystals
Photoconductivity
Electrons
Current voltage characteristics
Potential energy
dark current
photoconductivity
Temperature
Ionization

Keywords

  • charge transport
  • conductivity
  • deep levels
  • terahertz spectroscopy
  • transient spectroscopy

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biotechnology
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

Cite this

Kostina, S. S., Hanson, M. P., Wang, P. L., Peters, J. A., Valverde-Chávez, D. A., Chen, P., ... Wessels, B. W. (2016). Charge Transport Mechanisms in a Pb2P2Se6 Semiconductor. ACS Photonics, 3(10), 1877-1887. https://doi.org/10.1021/acsphotonics.6b00396

Charge Transport Mechanisms in a Pb2P2Se6 Semiconductor. / Kostina, Svetlana S.; Hanson, Micah P.; Wang, Peng L.; Peters, John A.; Valverde-Chávez, David A.; Chen, Pice; Cooke, David G.; Kanatzidis, Mercouri G; Wessels, Bruce W.

In: ACS Photonics, Vol. 3, No. 10, 19.10.2016, p. 1877-1887.

Research output: Contribution to journalArticle

Kostina, SS, Hanson, MP, Wang, PL, Peters, JA, Valverde-Chávez, DA, Chen, P, Cooke, DG, Kanatzidis, MG & Wessels, BW 2016, 'Charge Transport Mechanisms in a Pb2P2Se6 Semiconductor', ACS Photonics, vol. 3, no. 10, pp. 1877-1887. https://doi.org/10.1021/acsphotonics.6b00396
Kostina SS, Hanson MP, Wang PL, Peters JA, Valverde-Chávez DA, Chen P et al. Charge Transport Mechanisms in a Pb2P2Se6 Semiconductor. ACS Photonics. 2016 Oct 19;3(10):1877-1887. https://doi.org/10.1021/acsphotonics.6b00396
Kostina, Svetlana S. ; Hanson, Micah P. ; Wang, Peng L. ; Peters, John A. ; Valverde-Chávez, David A. ; Chen, Pice ; Cooke, David G. ; Kanatzidis, Mercouri G ; Wessels, Bruce W. / Charge Transport Mechanisms in a Pb2P2Se6 Semiconductor. In: ACS Photonics. 2016 ; Vol. 3, No. 10. pp. 1877-1887.
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