skip to main content

SciTech ConnectSciTech Connect

Title: Photon-enhanced thermionic emission from p-GaAs with nonequilibrium Cs overlayers

Photon-enhanced thermionic emission (PETE), which is promising for increasing the efficiency of solar energy conversion, is studied during cesium deposition on the As- and Ga-rich p-GaAs(001) surfaces and subsequent relaxation in the nonequilibrium Cs overlayer by means of photoemission quantum yield spectroscopy adapted for systems with time-variable parameters. Along with direct photoemission of “hot” electrons excited by light above the vacuum level, the spectra contain PETE contribution of “thermalized” electrons, which are excited below the vacuum level and emit in vacuum due to thermalization up in energy by phonon absorption. Comparing the measured and calculated spectra, the effective electron affinity and escape probabilities of hot and thermalized electrons are obtained as functions of submonolayer Cs coverage. The minima in the affinity and pronounced peaks in the escape probabilities are observed for Cs deposition on both the As- and Ga-rich surfaces. Possible reasons for the low mean values of the electron escape probabilities and for the observed enhancement of the probabilities at certain Cs coverages are discussed, along with the implications for the PETE device realization.
Authors:
; ;  [1] ;  [2]
  1. Rzhanov Institute of Semiconductor Physics, 630090 Novosibirsk (Russian Federation)
  2. (Russian Federation)
Publication Date:
OSTI Identifier:
22395577
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 105; Journal Issue: 25; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION; CESIUM; COMPARATIVE EVALUATIONS; ELECTRONS; EMISSION SPECTROSCOPY; GALLIUM ARSENIDES; LAYERS; PHONONS; PHOTOEMISSION; P-TYPE CONDUCTORS; RELAXATION; SOLAR ENERGY CONVERSION; SURFACES; THERMALIZATION; THERMIONIC EMISSION; VISIBLE RADIATION