Amorphous WO3 Films via Chemical Vapor Deposition from Metallorganic Precursors Containing Phosphorus Dopant

Amorphous WO 3 films, doped with phosphorus, have been synthesized by chemical vapor deposition of volatile, low-melting P-substituted tungsten carbonyls. The presence of a small quantity of dopant released by the precursor during its decomposition is sufficient to inhibit the crystallization of the tungsten oxide on the matrix (P/W 2−4 atom % on Si(100) and ca. 10 atom % on KGlass). The nature of the film is scarcely affected by the experimental conditions of deposition (namely p O 2 partial pressure) and the quantity of the P dopant is properly tuned by an appropriate choice of the molecular precursor, being in the order W(CO) 4 [P(OEt) 3 ] 2 (P/W 1/1) > W 2 (μ-PR 2 ) 2 (CO) 8 (P/W 1/4) > W(CO) 4 (PEt 3 ) 2 (P/W 1/10 on KGlass, 1/30 on Si). The films on KGlass exhibit interesting electrochromic properties with a maximum efficiency of 66 cm 2 /C.