Anti-Fowler Temperature Regime in Photoemission from n-Type Semiconductors with Surface Accumulation Layer
| Autor: | Klimentiy Shimanovich, M. Molotskii, Yossi Rosenwaks |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Condensed matter physics business.industry Inverse photoemission spectroscopy Fermi level Angle-resolved photoemission spectroscopy 02 engineering and technology Electron 021001 nanoscience & nanotechnology 01 natural sciences Condensed Matter::Materials Science symbols.namesake Semiconductor 0103 physical sciences symbols Condensed Matter::Strongly Correlated Electrons Work function Quantum efficiency 0210 nano-technology business Extrinsic semiconductor |
| Zdroj: | Journal of Modern Physics. :1020-1028 |
| ISSN: | 2153-120X 2153-1196 |
| Popis: | According to the Fowler theory and numerous experiments the quantum efficiency for photoemission from conductors increases with temperature. Here we show that an opposite temperature dependence is also possible, when the photoemission is from quasi-metallic surface accumulation layers of n-type semiconductors. This is due to the temperature dependence of the Fermi level energy in semiconductors. The Fermi level energy increases with decreasing temperature; this leads to a decrease of the semiconductor work function and consequently an increase of the quantum efficiency photoemission at constant value of absorbed light quanta of energy. We have calculated this effect for electron accumulation layer in n-GaN, induced by adsorption of positively charged cesium or barium ions. It is found that at low temperatures near liquid nitrogen, the quantum efficiency for photoemission increases to near 55%, which is comparable to the largest values, reported for any known photo-ca-thodes. This phenomenon may prove useful for efficient photo-cathodes operating at low temperatures. |
| Databáze: | OpenAIRE |
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