Preparation of highly (001)‐oriented photoactive tungsten diselenide (WSe2) films by an amorphous solid–liquid‐crystalline solid (aSLcS) rapid‐crystallization process. Issue 9 (16th May 2014)

• Record Type: Journal Article
• Authors: Bozheyev, Farabi; Friedrich, Dennis; Nie, Man; Rengachari, Mythili; Ellmer, Klaus
• Is Part Of: Physica status solidi. Volume 211:Issue 9(2014:Sep.)
• Page Start: 2013
• Page End: 2019
• Publication Date: 2014-05-16
• Subjects: Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201400016
• Languages: English
• ISSNs: 1862-6300

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pssa201400016-sec-0001" sec-type="section"> <p>Highly (001)‐textured tungsten diselenide WSe₂ thin films have been prepared by a two‐step process on quartz glass and TiN metallic back contacts, respectively. At first, X‐ray amorphous, selenium‐rich WSe_{2+<italic>x</italic>} films were deposited by reactive magnetron sputtering at room temperature onto a thin metal promoter film (Ni or Pd) and afterwards annealed in an H₂Se/Ar atmosphere. X‐ray diffraction and scanning electron microscopy show that highly (001)‐oriented WSe₂ films can be grown, which is caused by the formation of liquid promoter‐metal selenide droplets which dissolve tungsten or tungsten selenide at temperatures, higher than the eutectic temperature in the promoter metal–selenium system, followed by oversaturation and eventually crystallization of WSe₂ platelets. Time‐resolved microwave conductivity measurements show that the films are photoactive. The sum of the carrier mobilities of the best films <italic>µ</italic>_e + <italic>µ</italic>_h is in the range of 1–7 cm² V⁻¹ s⁻¹.</p> </sec> </abstract>