Crystal growth of Alga was achieved in an ionic liquid by vacuum vapor deposition. Alq(3) crystals of several tens of microns in size showed beautiful hexagonal morphologies, different from previous reports. The successful crystal growth can be explained by the enhanced migration of Alga molecules and moderate supersaturation within the ionic liquid. The Alq(3) crystal showed unique optical properties, such as a waveguide and blue-shift of the photoluminescence spectrum.