Na2KSb/CsxSb Interface Engineering for High-Efficiency Photocathodes | Sciact - CRIS-система Института катализа

Na2KSb/CsxSb Interface Engineering for High-Efficiency Photocathodes Научная публикация

Журнал

Physical Review Applied (PRApplied)
ISSN: 2331-7043 , E-ISSN: 2331-7019

Вых. Данные

Год: 2024, Том: 22, Номер: 2, Номер статьи : 024008, Страниц : DOI: 10.1103/physrevapplied.22.024008

Ключевые слова

Band diagram; Cesium; Cesium compounds; Chemical activation; Conduction bands; Electron affinity; Electrons; Energy gap; Field emission cathodes; Gallium arsenide; III-V semiconductors; Kinetic energy; Kinetics; Photoemission; Photons; Quantum efficiency; Semiconducting gallium

Авторы

Rozhkov S.A. ^1,2 , Bakin V.V. ¹ , Rusetsky V.S. ^1,3 , Kustov D.A. ¹ , Golyashov V.A. ^1,2,4 , Demin A.Yu. ³ , Scheibler H.E. ^1,2 , Alperovich V.L. ^1,2 , Tereshchenko O.E. ^1,2,4

Организации

1	Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia
2	Novosibirsk State University, Novosibirsk 630090, Russia
3	CJSC “EKRAN FEP”, Novosibirsk 630060, Russia
4	Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Koltsovo 630559, Russia

Информация о финансировании (2)

1	Министерство науки и высшего образования Российской Федерации (с 15 мая 2018)	FWUR-2024-0042
2	Российский научный фонд	22-12-20024 (122063000001-1)

Optical and photoemission measurements were performed on alkali antimonide Na2⁢KSb and Na2⁢KSb/Cs ⁢Sb photocathodes in order to determine their energy-band diagrams, elucidate the photoemission pathways, and explore the options for interface engineering in order to reach high quantum efficiencies of the photocathodes. This study is motivated by the recent discovery of optical orientation in Na2⁢KSb and emission of spin-polarized electrons from Na2⁢KSb/Cs ⁢Sb photocathodes [V.S. Rusetsky et al., Phys. Rev. Lett. 129, 166802 (2022)]. We have shown that the band gap of Na2⁢KSb at =295 K lies within the range of 1.40–1.44 eV. The Na2⁢KSb surface activation by the deposition of Cs and Sb results in effective electron affinity decrease by approximately 0.37 eV, and in an increase of the quantum efficiency up to 0.2 electrons per incident photon. The analysis of longitudinal energy distribution curves (EDCs) proves that the surface of activated Na2⁢KSb/Cs ⁢Sb photocathodes have negative effective electron affinity of approximately −0.1 and −0.25 eV at =295 and 80 K, respectively. EDC measurements under increasing photon energy ℏ⁢ demonstrate the transition of photoemission pathway from the surface states’ photoionization at ℏ⁢ < to the emission from the conduction-band bottom at ℏ⁢ ≈ and from the states with high kinetic energy in the conduction band at ℏ⁢ > . EDCs measured at 80 K reveal a highly directional photoelectron emission from the Na2⁢KSb/Cs ⁢Sb photocathode, as compared to the p-Ga⁢As(Cs,O) photocathode. This fact, along with the observed significant, by an order of magnitude, increase in the photoluminescence intensity under the Na2⁢KSb surface activation by Cs and Sb, indicates relatively weak diffuse scattering in the “quasiepitaxial” Cs ⁢Sb activation layer of a Na2⁢KSb/Cs ⁢Sb photocathode, compared to strong scattering in the amorphous (Cs,O) activation layer of a p-Ga⁢As(Cs,O) photocathode

Rozhkov S.A. , Bakin V.V. , Rusetsky V.S. , Kustov D.A. , Golyashov V.A. , Demin A.Y. , Scheibler H.E. , Alperovich V.L. , Tereshchenko O.E.
Na2KSb/CsxSb Interface Engineering for High-Efficiency Photocathodes
Physical Review Applied (PRApplied). 2024. V.22. N2. 024008 . DOI: 10.1103/physrevapplied.22.024008 WOS Scopus РИНЦ OpenAlex СКИФ ID

Поступила в редакцию:	9 апр. 2024 г.
Принята к публикации:	25 июн. 2024 г.
Опубликована в печати:	1 авг. 2024 г.
Опубликована online:	1 авг. 2024 г.

Web of science:	WOS:001285376300001
Scopus:	2-s2.0-85200767412
РИНЦ:	73363278
OpenAlex:	W4401251748
СКИФ ID:	3562

БД	Цитирований
OpenAlex	3
Scopus	4
Web of science	4