Prior to the 1960s and until the late 1990s, gas and argon-ion lasers were common and suffered from poor efficiencies (0.01%) and large sizes. In the 1960s, advancements in sapphire creation allowed researchers to deposit GaN on a base to create blue lasers, but a lattice mismatch between the structures of gallium nitride and sapphire created many defects or, leading to short.