Enhanced photoemission from surface modulated GaAs:Ge

Abstract

Abstract The present work reports the evolution and growth of GeGaAs(O) polytype nanoislands over GaAs p‐type substrate with photoemission application in mind. Several morphological transformations from NIs to simultaneously present nanopits/holes are observed as a function of annealing parameters that is, temperature (350‐800°C) and time (5‐90 minutes). Structural and elemental analyses are executed using atomic force microscopy, scanning electron microscopy and energy dispersive X‐ray spectroscopy. Photoemission current of the nanostructured surfaces, measured upon exposure from 265 nm light emitting diode, is found to depend on the nanoislands size, which in turn depends on the annealing parameters. A maximum photoelectric emission is obtained for structure annealed at 650°C for 60 minutes, upon which an increment of roughly two orders of magnitude is observed.

Keywords

• AFM
• GaAsGe
• nanostructure
• photoemission
• SEM