photovoltaicsPronunciation: /ˌfəʊtə(ʊ)vɒlˈteɪɪks/Definition of photovoltaics noun [treated as singular] the branch of technology concerned with the production of electric current at the junction of two substances. [treated as plural] devices having a photovoltaic junction. photovoltaics in other Oxford dictionaries Definition of photovoltaics in the US English dictionary