Inherent Buffer-layer Formation on Chalcopyrite Absorbers

2009 ◽  
Vol 1210 ◽  
Author(s):  
Christian Pettenkofer ◽  
Andreas Hofmann ◽  
Carsten Lehmann ◽  
Alexandra Dombrowa
Keyword(s):  
Buffer Layer ◽  
Photoelectron Spectroscopy ◽  
Band Alignment ◽  
Initial Growth ◽  
Layer Formation ◽  
Low Energy Electron Diffraction ◽  
Photovoltaic Applications ◽  
Step Growth ◽  
Low Energy Electron ◽  
Excess Sulfur

AbstractWe report on epitaxial growth of ZnO on polycrystalline and (112) orientated CuInS2 and CuInSe2 thin films. Step-by-step growth and investigation by photoelectron spectroscopy (PES) and low energy electron diffraction (LEED) provided information on the growth mode and the electronic structure of the ZnO-CuInS2-interface. During the initial growth no ZnO is deposited. Instead a monolayer of ZnS is formed by depletion the CuInS2 surface of excess sulfur. Thereafter, the ZnO growth starts on the ZnS buffer layer. The band alignment derived from PES shows that the ZnS buffer layer is thin enough to provide a beneficial band alignment for photovoltaic applications. CuInSe2 (112) samples showed a similar behaviour, but at the chosen deposition temperature of 450°C only ZnSe growth is detected. At lower temperatures ZnO growth on top of ZnSe is observed. XPEEM experiments show an inhomogeneous interface.

Surface Band Structure Studies of Si Rich Reconstructions on 4H-SiC(1-100)

2005 ◽  
Vol 483-485 ◽  
pp. 547-550 ◽  
Author(s):  
Konstantin V. Emtsev ◽  
Thomas Seyller ◽  
Lothar Ley ◽  
A. Tadich ◽  
L. Broekman ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Electron Diffraction ◽  
Photoelectron Spectroscopy ◽  
Low Energy ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Surface Band ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Different Temperatures ◽  
Low Energy Electron

We have investigated Si-rich reconstructions of 4H-SiC( 00 1 1 ) surfaces by means of low-energy electron diffraction (LEED), x-ray photoelectron spectroscopy (XPS), and angleresolved ultraviolet photoelectron spectroscopy (ARUPS). The reconstructions of 4H-SiC( 00 1 1 ) were prepared by annealing the sample at different temperatures in a flux of Si. Depending on the temperature different reconstructions were observed: c(2×2) at T=800°C, c(2×4) at T=840°C. Both reconstructions show strong similarities in the electronic structure.

Fluorine Atom Addition to the Diamond (111) Surface

1992 ◽  
Vol 242 ◽  
Author(s):  
Andrew Freedman ◽  
Gary N. Robinson ◽  
Charter D. Stinespring
Keyword(s):  
Electron Diffraction ◽  
Photoelectron Spectroscopy ◽  
Fluorine Atom ◽  
Low Energy ◽  
Diamond Surface ◽  
X Ray ◽  
Low Energy Electron Diffraction ◽  
Atomic Fluorine ◽  
Low Energy Electron ◽  
Diffraction Patterns

ABSTRACTDiamond (111) surfaces with the dehydrogenerated 2×1 reconstruction have been exposed to a beam of atomic fluorine at 300 K. The uptake of fluorine, as measured using X-ray photoelectron spectroscopy, is quite efficient and saturates at a coverage of less than a monolayer. Low energy electron diffraction patterns indicate that fluorine termination of the diamond surface produces a lxi bulk-like reconstruction in contrast to the disordered surface produced on the (100) surface.

INCOMMENSURATE METALLIC SURFACTANT LAYER ON TOP OF InN FILM

2006 ◽  
Vol 13 (06) ◽  
pp. 815-818 ◽  
Author(s):  
Y. LIU ◽  
J. WANG ◽  
M. H. XIE ◽  
H. S. WU
Keyword(s):  
Electron Diffraction ◽  
Surface Structure ◽  
Buffer Layer ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron Diffraction ◽  
Incommensurate Structure ◽  
Low Energy Electron ◽  
Gan Buffer Layer

The surface structure of InN film heteroepitaxially grown on a GaN buffer layer by MBE is followed by low energy electron diffraction (LEED). The metallic surfactant layers on top of the InN surfaces show an incommensurate structure rather than being disordered. The metal in the incommensurate structure induces additional diffraction spots in the LEED. Based on the Auger experiments, not only In atoms but also Ga are present on the surface of the InN films.

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