Abstract: The light brightness of a semiconductor LED is increased by employing a light transmitting window comprising ZnO. In another embodiment, current crowding is reduced, efficiency increased and reliability (lifetime) increased by forming a thin semiconductor transition layer to reduce contact resistance between an overlying transparent window layer and an underlying transparent current diffusion layer formed on a double heterostructure light generation region. Optimum performance is achieved employing the transition layer with a ZnO transparent window layer.