In　this　work,　we　demonstrate　the　application　of　water　vapor　doped　indium　oxide,　alloyed　with　transition　metal　element　M　(IMO),　as　highly　transparent　conductive　oxide　(TCO)　films　incorporated　in　bifacial　silicon　heterojunction　(SHJ)　solar　cells.　By　adding　water　vapor　and　oxygen　gas　into　sputtering　gas　mixture,　both　electrical　and　optical　properties　of　IMO　film　can　be　improved　significantly.　IMO　films　are　characterized　by　sheet　resistivity,　Hall　mobility　and　carrier　density,　crystallinity,　and　spectral　transmittance.　Finally,　we　obtained　a　0.64　mA/cm2　gain　in　JSC　with　optimal　water　vapor　doped　IMO　film　on　n-side　of　SHJ　cell,　resulting　in　a　0.31%　increase　in　solar　cell　conversion　efficiency.　©　2018　IEEE.