Visible light-emitting diodes grown on optimized del(x)[InxGa1-x]P/GaP epitaxial transparent substrates with controlled dislocation density

Epitaxial transparent-substrate light-emitting diodes (ETS-LEDs) have been fabricated on optimized graded buffers of InxGa1-xP on GaP (del(x)[InxGa1-x ]P/GaP) that feature controlled threading dislocation densities of 3 x 10(6 ) cm(-2). The ETS-LEDs show increasing efficiency from 575 nm to 655 nm, in marked contrast to previous reports where performance drops above 600 nm, and feature the lowest spectral widths ever reported in del(x)[InxGa1-x]P/G aP. The improvement over earlier reports is attributed to large mean disloc ation spacings in optimized del(x)[InxGa1-x]P/GaP, which are an order of ma gnitude greater than the mean carrier diffusion length. A slight performanc e decline remains at 655 nm, but the overall performance of this first gene ration of ETS-LEDs is promising.