A new series of organometallic/inorganic hybrid Langmuir-Blodgett (LB) films containing an organometallic gold(i) aryleneethynylene metal complex (OMA) as the π-conjugated organometallic molecule and a polyoxometalate (POM, POM = H₃BW₁₂O₄₀, H₆As₂W₁₈O₆₂, or H₆P₂Mo₁₈O₆₂) of the Keggin and Dawson structure as the inorganic composite, were prepared and characterized by π–A isotherms, UV-vis absorption spectra, photoluminescence spectra, atomic force microscopy imaging, scanning tunnelling microscopy, and surface photovoltage spectroscopy. Our experimental results indicate that stable, well defined and well organized Langmuir and LB films are formed in pure water and polyoxometalate subphases. There is a quenching effect in the luminescence of the gold(i) complex when it is made into the LB films. The OMA/POM hybrid LB films display strong photovoltage effect in the UV-vis region. The photovoltage response of OMA/H₆As₂W₁₈O₆₂ can be as high as 3338 μV. OMA/POM monolayer films show good electrical conductivity, and the tunnelling current for a OMA/H₃BW₁₂O₄₀ monolayer film amounts to 50 to approximately –100 nA when the voltage is set at ±9 V.