AlGaInP LEDs using reactive thermally evaporated transparent conducting indium tin oxide (ITO)

Abstract

Reactive thermally evaporated transparent conducting indium tin oxide (ITO) layers are used as window material and for current spreading layers on AlGaInP light emitting diodes (LEDs). The sheet resistance of the ITO films deposited is of the order of 4.5 Ω/□ with up to 90% transmission in the visible region of the spectrum. The optimum thickness of the p-type and n-type AlGaInP cladding and the top p+-GaAs epitaxial layers were determined. The LEDs fabricated emit light with a peak wavelength (λp) at 600 nm and a full width at half maximum (FWHM) of 15 nm. A forward voltage of 1.71 V at 20 mA was obtained. In all cases, the devices incorporating the ITO layer gave a marginally greater output (10%) than the standard non-ITO devices. [This article has been reprinted due to the significance of the corrections. The article appears in 1995, issue 25, p.2210–2212.]