Research on Cs/O activation process of near-infrared In0.53Ga0.47As photocathodes
作者： Liang Chen , Yang Shen , Xiaodong Yang , Muchun Jin , Songmin Liu
DOI: 10.1016/J.JALLCOM.2020.154869
关键词:
摘要: Abstract We report a systematic theoretical investigation on the activation mechanism of near-infrared In0.53Ga0.47As photocathodes. Adsorption energies, dipole moments, work functions, density states, band structures and electron affinity Cs/O co-adsorption (001) surface photocathodes are investigated. First-principles calculation results indicate that structural stability is greatly enhanced when oxygen atoms adsorb Cs-covered surface. The incorporation atom helps lower function further to achieve true NEA state. Moreover, two adatom-induced dipoles, namely [Csn+-In0.53Ga0.47Asn−] [Cs+-O2--Cs+], also adopted explain relationship between adatoms substrate. HOMO LUMO levels can move downward bending region enlarged after co-activation. Meanwhile, new energy bands appear in deep valence due joint effect Cs 5s, 5p, O 2s 2p state electrons. Finally, experiments carried out photocurrent curves during procedure recorded. change closely related variation, which affects photoemission In order clearly show affinity, variation barrier height InGaAs with adlayer given.
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