Surface states and accumulation nanolayer induced by Ba and Cs adsorption on the n-GaN(0001) surface

Anti-Fowler Temperature Regime in Photoemission from <i>n</i>-Type Semiconductors with Surface Accumulation Layer

“…For calculating the photoemission we assume that the exciting light is S-polarized, where the square of matrix element S M of the optical transition is described by the following equation [12]:…”

“…However, the authors of Ref [10] [11] [12] do not report on the exact value of QE, but only report that the maximal QE of the Cs/n-GaN system is comparable and even exceeds the QE for highly-efficient source of electron GaAs photo-cathodes, which can reach 50% [14]. Therefore, we assume that the QE for the Cs/n-GaN system is also not less than 50% at room temperature for photon energy 3.1 eV (5) shows that in the conventional Fowler regime for a temperature range from 300 to 500 K the QE value increases by only on 0.7%.…”

“…This phenomenon may be useful for increasing the photo emission from photo-cathodes operating at low temperatures. [12]. The reported value of photoemission threshold from surface AL at room temperature, induced by cesium coverage with thickness of 0.5 ML is 1.4 eV, which corresponds to the infrared range with wavelength 885 nm AL th λ = .…”

Synchrotron radiation photoemission study of the ultrathin Cs/InN interface

“…For III nitrides, accumulation layers were revealed at the clean InN surface [23,24] and formed via adsorption at both the GaN and AlGaN surfaces [28,29]. Adsorption of alkali metals Cs, K on the InN surface has been recently investigated in [21,26,27] in which the significant modification of the surface electronic structure has been demonstrated.…”

Электронная структура наноинтерфейса Cs/n-GaN(0001)

“…Было показано, что адсорбция Cs на p-GaN(0001) приводит к сильному изгибу зон и подавлению собственных поверхностных состояний подложки [14]. Поверхностные состояния вблизи уровня Ферми (E F ), индуцированные адсорбцией Cs были найдены методом пороговой фотоэмиссионной спектроскопии [15].…”