Gate tunable photovoltaic effect in MoS2 vertical p-n homostructures

Simon A. Svatek, Elisa Antolin, Der Yuh Lin, Riccardo Frisenda, Christoph Reuter, Aday J. Molina-Mendoza, Manuel Muñoz, Nicolás Agraït, Tsung Shine Ko, David Perez De Lara, Andres Castellanos-Gomez

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Abstract

p-n junctions based on vertically stacked single or few-layer transition metal dichalcogenides (TMDCs) have attracted substantial scientific interest. Due to the propensity of TMDCs to show exclusively one type of conductivity, n- or p-type, heterojunctions of different materials are typically fabricated to produce diode-like current rectification and photovoltaic response. Recently, artificial, stable and substitutional doping of MoS2 into n- and p-type materials has been demonstrated. MoS2 is an interesting material for use in optoelectronic applications due to its potential of low-cost production in large quantities, strong light-matter interactions and chemical stability. Here we report the characterization of the optoelectronic properties of vertical homojunctions made by stacking few-layer flakes of MoS2:Fe (n-type) and MoS2:Nb (p-type). The junctions exhibit a peak external quantum efficiency of 4.7% and a maximum open circuit voltage of 0.51 V; they are stable in air; and their rectification characteristics and photovoltaic response are in excellent agreement with the Shockley diode model. The gate-tunability of the maximum output power, the ideality factor and the shunt resistance indicate that the dark current is dominated by trap-assisted recombination and that the photocurrent collection depends strongly on the spatial extent of the space charge region. We demonstrate a response time faster than 80 ms and highlight the potential to integrate such devices into quasi-transparent and flexible optoelectronics.

Original languageEnglish
Pages (from-to)854-861
Number of pages8
JournalJournal of Materials Chemistry C
Volume5
Issue number4
DOIs
Publication statusPublished - 2017 Jan 1

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Chemistry

Cite this

Svatek, S. A., Antolin, E., Lin, D. Y., Frisenda, R., Reuter, C., Molina-Mendoza, A. J., Muñoz, M., Agraït, N., Ko, T. S., De Lara, D. P., & Castellanos-Gomez, A. (2017). Gate tunable photovoltaic effect in MoS2 vertical p-n homostructures. Journal of Materials Chemistry C, 5(4), 854-861. https://doi.org/10.1039/c6tc04699a