Single crystals of 2D/3D-blended perovskite were grown by inverse temperature crystallization method, and used this material for the fabrication of perovskite solar cells (PSC). Although, 3D perovskite is known for its high photovoltaic efficiency due to intense visible light absorbance, the hydrophilic organic cation in its structure makes it susceptible to rapid moisture induced structural degradation. When the 2D perovskite, possessing the long chains of hydrophobic organic molecule is incorporated in the 3D counterpart, moisture induced degradation is reduced, but with increased grain boundaries. The novelty of this work is to grow the single crystal of the 2D/3D-blended perovskite, aiming to enhance the carrier mobility by reducing the grain boundaries, trap state densities, and charge recombination, while preserving the improved material stability. PSCs with polycrystalline 3D perovskite, single crystal of 3D perovskite, and single crystal of 2D/3D-blended perovskite yielded efficiencies of 4.55%, 6.37% and 5.37% respectively.