In the ionic Hubbard model, the onsite repulsion U , which drives a Mott insulator and the ionic potential V , which drives a band insulator, compete with each other to open up a window of charge fluctuations when U ∼ V . We study this model on square and cubic lattices in the limit of large U and V , with V ∼ U . Using an effective Hamiltonian and a slave boson approach with both doublons and holes, we find that the system undergoes a phase transition as a function of V from an antiferromagnetic Mott insulator to a paramagnetic insulator with strong singlet correlations, which is driven by a condensate of "neutral" doublon-hole pairs. On further increasing V , the system undergoes another phase transition to a superconducting phase driven by condensate of "charged" doublons and holes. The superfluid phase, characterized by presence of coherent (but gapped) fermionic quasiparticle, and hc/e flux quantization, has a high Tc ∼ t which shows a dome shaped behaviour as a function of V . The paramagnetic insulator phase has a deconfined U(1) gauge field and associated gapless photon excitations. We also discuss how these phases can be detected in the ultracold atom context.A dramatic observable effect of strong interactions between fermions on a lattice is the formation of Mott insulating states, where charge motion is suppressed due to large on-site repulsion [1, 2]. This effect occurs in a large class of materials like transition metal oxides [3][4][5][6], including parent compounds of cuprate high T c superconductors [5, 6]. Recently, Mott insulators have been observed in systems of ultracold fermions on optical lattices [7, 8], where the repulsive Fermi Hubbard model with tuneable Hamiltonian parameters can be implemented faithfully.A theoretically challenging problem is to ascertain the fate of a system in proximity to a Mott insulator, where charge fluctuations are induced by different means; e.g. by doping the system away from commensurate filling (high T c cuprate superconductors) [9, 10] or by changing ambient pressure (organic superconductors) [11] or simply by changing the ratio of the interaction energy scale to the kinetic energy scale (ultracold atomic systems) [12]. Experimentally, when charge fluctuation is induced around a Mott insulator, competing order parameters lead to a very rich phase diagram [11,13] with an ubiquitous presence of superconducting phases [11,14,15].The Ionic Hubbard model is defined on bipartite lattices [16], where, in addition to the kinetic energy (∼ t) and the local Hubbard repulsion (∼ U ), the fermions are affected by a constant one-body potential difference between the two sublattices (∼ V ). This model, originally proposed to explain ionic to neutral transitions [16,17], has also been used to describe ferroelectric transitions [18][19][20]. It has recently been implemented in the context of ultracold atoms [21] where the relative strengths of U and V can be tuned controllably. In the absence of interactions, this model describes a band insulator at half-filling due to d...