Si photodetectors imprinted with ITO nanodomes for enhanced photodetection at NIR wavelengths

The p-n junction Si photodetector coated with ITO nanodomes was fabricated using large scale applicable nano imprint method. The ITO/Ni/ITO layers were deposited on both the ITO nanodomes and on the planar Si substrate. All the ITO nanodomes were electrically connected via the bottom ITO layer. The FESEM images showed the uniform array and identical surroundings of ITO nanodomes structures along with Ni and ITO layers. The highest rectification ratio of 1511.10 was obtained as the ITO nanolens focused the incident light effectively into the rectifying junction. The planar device showed the lowest reverse saturation current of 2.4 µA. The quantum efficiencies of the ITO nanodome coated Si detector were greater than that of planar ITO film coated Si devices. The presented photodetector showed the maximum internal quantum efficiency of 72.2% at 600 nm. The photoresponse of the device were excellent at a NIR wavelength of 900 nm. The Si photodetector with ITO nanodome coating would be the best device for long wavelength photodetection applications.