Scanning tunneling microscope induced light emission from GaAs(1 1 0) surfaces

Light emission phenomena, which are induced by injection of electrons or holes from a scanning tunneling microscope (STM) tip, have been investigated on GaAs(1 1 0) surfaces at 78 K. To collect the emitted photons, a sharpened optical-fiber tip covered with indium-tin-oxide thin films is employed as an STM probe. We have obtained atomic-resolved STM images of the GaAs(1 1 0) surfaces using the conductive fiber tip at 78 K, simultaneously collected the emitted photons. The different luminescence nature between p- and n-doped GaAs(1 1 0) surfaces is presented in this paper.