Complex sentence: Researchers at Taiwan National Central University and Epistar Corp are developing a way to lessen the efficiency droop by using ceramic aluminium nitride (AlN) substrates, which are more thermally conductive than the commercially used sapphire.
Split into simpler sentences: Researchers at Taiwan National Central University and Epistar Corp are developing a way to lessen the efficiency droop. They are doing this using ceramic aluminium nitride (AlN) substrates, which are more thermally conductive than the commercially used sapphire.