ˌɛsˈɛn sˈiː hɐz ɛɡzˈɪbɪɾᵻd ðə hˈaɪɪst θˌɜːmoʊɪlˈɛktɹɪk mətˈɪɹiəl ɪfˈɪʃənsi, mˈɛʒɚd baɪ ðə jˈuːnɪtləs zˌiːtˈiː pɚɹˈæmɪɾɚ, ʌv ˌɛni nˈoʊn mətˈɪɹiəl tˈɪldə tˈuː.sˈɪksti tˈuː æt nˈaɪnhˈʌndɹɪd twˈɛnti θɹˈiː kˈeɪ ɐlˈɔŋ ðə bˈiː ˈæksɪs ænd tˈɪldə tˈuː.θɹˈiː ɐlˈɔŋ ðə sˈiː ˈæksɪs.
SnSe has exhibited the highest thermoelectric material efficiency, measured by the unitless ZT parameter, of any known material (~2.62 at 923 K along the b axis and ~2.3 along the c axis).