Passivation of recombination active PdSe x centers in (001)-textured photoactive WSe 2 films

Farabi Bozheyev, Mythili Rengachari, Sean P. Berglund, Daniel Abou-Ras, Klaus Ellmer

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


Highly (001)-textured tungsten diselenide WSe 2 thin films are crystallized from X-ray amorphous WSe x films with Pd-promotion in an H 2 Se atmosphere. During the crystallization process, the liquid promoter PdSe x is driven to the grain boundaries due to the lateral growth of WSe 2 platelets and their coalescence. The photoactivity of the WSe 2 films is limited by the PdSe x crystallites at the grain boundaries of WSe 2 platelets. The presence of the PdSe x crystallites leads to a metal like behavior of the conductivity versus temperature, whereas their etching leads to a semiconducting behavior of the WSe 2 film. After selective etching of these crystallites, the more active WSe 2 sites (edges, cavities) are exposed, enhancing the electron transfer to the electrolyte. A photocurrent density of 2 mA cm −2 at 0.35 V vs. reversible hydrogen electrode (RHE) is observed in sulfuric acid (0.5 M H 2 SO 4 ) using Fe 2+ /Fe 3+ as redox pair under 1 sun (Air Mass (AM) 1.5, 100 mW cm −2 ) illumination.

Original languageEnglish
Pages (from-to)284-289
Number of pages6
JournalMaterials Science in Semiconductor Processing
Publication statusPublished - Apr 2019

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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