Rapid crystallization of WS2 films assisted by a thin nickel layer: An in situ energy‐dispersive X‐ray diffraction study

By rapid thermal crystallization of an amorphous WS3+x film, deposited by reactive magnetron sputtering at temperatures below 150 °C, layer‐type semiconducting tungsten disulfide films (WS2) were grown. The rapid crystallization was monitored in real‐time by in situ energy‐dispersive X‐ray diffraction. The films crystallize very fast (>40 nm/s), provided that a thin nickel film acts as nucleation seeds. Experiments on different substrates and the onset of the crystallization only at a temperature between 600 and 700 °C points to the decisive role of seeds for the textured growth of WS2, most probably liquid NiSx drops. The rapidly crystallized WS2 films exhibit a pronounced (001) texture with the van der Waals planes oriented parallel to the surface, leading to photoactive layers with a high hole mobility of about 80 cm2/Vs making such films suitable as absorbers for thin film solar cells. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)