Highly transparent Pt ohmic contact to InGaN / GaN blue light - emitting diodes

We report on the fabrication and characterization of InGaN/GaN multiple quantum well light-emitting diode (LED) with a highly transparent Pt ohmic contact as a current spreading layer. The value of light transmittance of a Pt thin film with a thickness of 8 ㎚ on p-GaN was measured to be 85% at 450 ㎚. The peak wavelength and the full-width at half-maximum (FWHM) of the emission spectrum of the LED at 20 ㎃ were 453 ㎚ and 23 ㎚, respectively. Pt-contacted LEDs show good electrical properties and high light-output efficiency compared to Ni/Au-contacted ones. These results suggest that a Pt thin film can be used as an effective current spreading layer with high light-transparency.