Optoelectronic properties of Ni–GaP diodes with a modified surface

• High-sensitive surface-barrier Ni–GaP device was developed with a low-cost technology.
• Surface modification improved the optoelectronic properties of the sample.
• The current/illumination ratio remains linear for variation of illumination by 5 orders of magnitude.

We report the promising results for Ni–GaP Schottky diode structures manufactured on the substrates with chemically-etched nano-scale surface formations that are responsible for a clearly marked luminescence band located at the energy exceeding the band gap of the bulk GaP. The other peculiarity produced by surface patterning concerns a remarkable redshift of material's optical absorption edge. At the room temperature, the height of potential barrier for Ni–GaP structure is 1.8 eV, with the monochromatic sensitivity peaking at 0.35 A/W. The comparative study of diode performance under different light sources exhibited the pronounced linear photocurrent-illumination dependence for about five orders of illumination magnitude, evidencing good optical and electrical quality of Ni–GaP diodes with surface-modified semiconductor substrate.