Photoemission Study of the α-Sn/Cdte(110) Interface Growth

1987 ◽  
Vol 94 ◽  
Author(s):  
Ming Tang ◽  
David W. Niles ◽  
Isaac Hernández-Calderón ◽  
Hartmut Hóchst

ABSTRACTAngular Resolved Photoemission Spectroscopy with Synchrotron radiation has been used to study the MBE growth of α-Sn on CdTe(110). Sn grows epitaxially and the Fermi level pins at 0.72eV above the CdTe valence band maximum. Outdiffusion or segregation of Cd in the α-Sn layer is not observed. For small Sn coverages the Sn4d core spectra show a second component which may be due to the initial interfacial growth of SnTe.

1990 ◽  
Vol 04 (18) ◽  
pp. 1133-1136
Author(s):  
S.B. ZHANG

Recent theory predicted that the Ga and B antisites in GaAs are bistable. As the Fermi level is lowered towards the valence-band maximum, a structural change from fourfold to threefold coordination will occur. The Ga antisite will undergo an atomic exchange in the presence of an As interstitial.


1992 ◽  
Vol 260 ◽  
Author(s):  
David W. Niles ◽  
Art J. Nelson ◽  
C. Richard Schwerdtfeger ◽  
Hartmut Höchst ◽  
Dennis Rioux

ABSTRACTWe studied Mo and Ni contacts to p-type CuInSe2(112) with angular-resolved synchrotron radiation ultraviolet photoemission spectroscopy in the range 40 eV hv < 120 eV. By varying the photon energy, we determined that emission from the CuInSe2 Г-point in the Brillouin zone occurs for hv = 60 eV, and identified emission from the valence band maximum. After depositing Ni and Mo, we found that the conduction band minimum of the CuInSe2 very nearly aligned to the Fermi edges of both metals, giving Schottky barriers Vsb = 1.05 ±0.1 eV. The interfaces are not atomically abrupt, as seen by the outdiffusion of Se into the refractory metal overlayers and the formation of In-Mo and In-Ni alloys.


1987 ◽  
Vol 94 ◽  
Author(s):  
David W. Niles ◽  
Ming Tang ◽  
Hartmut Höchst

ABSTRACTWe have used angular resolved ultraviolet photoemission spectroscopy to study the epitaxial growth of Si on GaP(110). Surface state emission obscures the top of the valence band (TVB). The Fermi level for the clean GaP(110) surface is 1.20±0.05eV above the TVB. 1ML (monolayer) of Si pins the Fermi level position at 1.40±0.05eV above the TVB. Further deposition of Si leads to a valence band discontinuity ΔEv=1.07 ±0.10eV.


2012 ◽  
Vol 86 (24) ◽  
Author(s):  
J. Dahl ◽  
M. Kuzmin ◽  
J. Adell ◽  
T. Balasubramanian ◽  
P. Laukkanen

1992 ◽  
Vol 259 ◽  
Author(s):  
A. Hughes ◽  
T-H. Shen ◽  
C.C. Matthai

ABSTRACTThe electronic density of states (DOS) for the Si(111) (√3×√3)-Sb system has been calculated using the tight binding method in the Extended Hiickel Approximation. We find that there is a gap of about 0.8eV between the valence band maximum (VBM) and a surface state. This is in contrast with the case of the unreconstructed (lxl) surface where the Fermi level lies at the surface state.


2018 ◽  
Vol 6 (15) ◽  
pp. 6299-6308 ◽  
Author(s):  
Félix del Prado ◽  
Ana Cremades ◽  
David Maestre ◽  
Julio Ramírez-Castellanos ◽  
José M. González-Calbet ◽  
...  

Shift of the Fermi level towards the valence band maximum (VBM) of around Φ ∼ 0.2 eV.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shun-Chang Liu ◽  
Chen-Min Dai ◽  
Yimeng Min ◽  
Yi Hou ◽  
Andrew H. Proppe ◽  
...  

AbstractIn lead–halide perovskites, antibonding states at the valence band maximum (VBM)—the result of Pb 6s-I 5p coupling—enable defect-tolerant properties; however, questions surrounding stability, and a reliance on lead, remain challenges for perovskite solar cells. Here, we report that binary GeSe has a perovskite-like antibonding VBM arising from Ge 4s-Se 4p coupling; and that it exhibits similarly shallow bulk defects combined with high stability. We find that the deep defect density in bulk GeSe is ~1012 cm−3. We devise therefore a surface passivation strategy, and find that the resulting GeSe solar cells achieve a certified power conversion efficiency of 5.2%, 3.7 times higher than the best previously-reported GeSe photovoltaics. Unencapsulated devices show no efficiency loss after 12 months of storage in ambient conditions; 1100 hours under maximum power point tracking; a total ultraviolet irradiation dosage of 15 kWh m−2; and 60 thermal cycles from −40 to 85 °C.


1998 ◽  
Vol 512 ◽  
Author(s):  
C. Koitzscht ◽  
M. O'Brient ◽  
D. Johri ◽  
A. Stoltzt ◽  
R. Nemanicht

ABSTRACTPhotoemission spectroscopy (UPS) was used to investigate the interface properties of deposited silicon on hexagonal 6H-silicon carbide. SiC cleaned in Si flux from a molecular beam epitaxy (MBE) system was used for this study. All processes were accomplished in an ultra high vacuum integrated system that allowed all cleaning, deposition, and analysis to be completed without exposure to ambient atmosphere. Thicknesses of sub- to multiple monolayers were deposited and the valence band structure was investigated. The valence band maximum (VBM) was observed to shift for Si depositions greater than 1 monolayer. The VBM offset was determined to be 2.4eV for a layer of 60Å Si on SiC. Furthermore, the prominent surface state feature of the silicon carbide (0001)si surface is reduced after Si deposition. The results are discussed in terms of the electronic properties of the Si – SiC interface.


RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4422-4427 ◽  
Author(s):  
Lijing Zhang ◽  
Xiufang Zhu ◽  
Zhihui Wang ◽  
Shan Yun ◽  
Tan Guo ◽  
...  

The uniform distribution of S dopants elevated the valence band maximum by mixing S 3p with the upper valence band states of ZnO. The valence band maxima of S–ZnO was 0.37 eV higher than that of ZnO.


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