Electron spectroscopy of conduction electrons excited by visible light utilizing NEA surface

Abstract

In this paper we propose an angle-resolved photoemission spectroscopy to observe the conduction electrons emitted from a surface of negative electron affinity state. In actual, we have measured conduction electrons in a GaAs bulk crystal and obtained the electron dispersion around Γ point. In addition, we could also observe hot electrons excited by the light which energy was much larger than band gap energy. These results suggest that the method we proposed is one of the most powerful tools for the evaluation method of the conduction band.Index Terms -intermediate-band solar cells, negative electron affinity surface, photoelectron spectroscopy, III-V compound semiconductor.

Measurement of energy distribution of conduction electrons in superlattice by visible-light photoemission spectroscopy

“…We have proposed visible-light photoemission spectroscopy (VPS), which is a novel angle-resolved photoemission spectroscopy to measure energy distribution of conduction electrons [3]. In the VPS, we utilize a surface with a negative electron affmity (NEA) state to emit the conduction electrons into a vacuum from a semiconductor.…”