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• W2034866466 endingPage "1580" @default.
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• W2034866466 abstract "Device-grade ternary Cu–Ga–Se chalcopyrite thin films used for photovoltaic energy conversion have been prepared by a novel chemical close-spaced vapor transport (CCSVT) technique developed for a deposition on areas of up to 10×10 cm2. A two-step process has been developed which allows the fine tuning of the film composition and the electronic properties. The extension of deposition times in the two-step process led to final film compositions with [Ga]/[Cu] ratios ranging from 0.9 to 5.7, allowing the study of the structural phase transitions. In this paper the main focus of interest is related to the material properties of the device-grade thin films prepared by CCSVT technique. We present our recent studies on (i) the growth, compositional, structural and electronic structural properties, (ii) the degradation under ambient conditions and (iii) the feasibility of n-type doping this p-type semiconducting material by germanium. Thin films were grown with chalcopyrite (1:1:2) and CuGaSe2-related defect compound structures (DC) with stoichiometries of CuGa3Se5 and CuGa5Se8. In order to derive the DC structure, X-ray and neutron powder diffraction investigations have been carried out on powders of these CuGaSe2-related compounds grown by elemental synthesis (powder) and CCSVT (thin films), respectively. We found no hints for an ordering of defects, as proposed in the past and giving name to the so-called Ordered Defect Compounds (ODC) in this and related structures. From our results a growth model is presented for CuGa3Se5 formation in gallium-rich CCSVT-grown CuGaxSey films. The chemical and electronic surface and interface structure of CuGaSe2 thin films with bulk [Ga]/[Cu] ratios between 0.94 and 1.39 is investigated by X-ray and UV-excited photoelectron spectroscopy (XPS and UPS, respectively). A transition of the Cu:Ga:Se surface composition from 1:1:2 for the Cu-rich bulk sample to 1:3:5 for the sample with the highest bulk [Ga]/[Cu] ratio is observed. Simultaneously, a downward shift of the valence band maximum position with respect to the Fermi energy is found. The comparison of the estimated conduction band minimum with that of CdS reveals the formation of a pronounced “cliff-like” conduction band offset at the respective interface. Furthermore, the CuGaSe2 thin film degradation under ambient as well as under thermal conditions of CuGaSe2 thin films has been studied by XPS. During thermal oxidation, the formation of predominantly Ga2O3 and some amount of SeO2 were observed, but no copper oxides could be detected in the near-surface region of the thin films. The same oxides are found after native oxidation in air under ambient conditions. An additional sodium oxide compound formed at the thin film surface, NaxO and Na2CO3 after thermal and native oxidation, respectively. Germanium ion implantation technique of the near-surface region of CuGaSe2 thin films has been used in order to prove the feasibility of n-type doping. In photoluminescence (PL) studies, the occurrence of a new emission line is identified as Ge related and explained as a donor–acceptor-pair (DAP) recombination. The precise role the Ge is playing in this doping of CuGaSe2 is revealed by X-ray absorption spectroscopy (XANES and EXAFS) and ab initio calculations based on the density functional theory. The studies indicate that the incorporated Ge atoms preferentially occupy Ga sites when relaxation around the dopant is taken into account. Additionally, our corresponding theoretical band structure model predicts the existence of additional localized electronic acceptor and donor defect bands within the band gap of CuGaSe2 originating from a strong covalent interaction between Ge 4s and Se 4p states for Ge atoms tetrahedrally surrounded by the Se nearest-neighbor atoms. A theoretically predicted anti-bonding Ge–Se4sp3 defect band appearing well above the Fermi level for the Ge1+Ga point defect system can be directly linked to a Ge-dopant-related donor–acceptor-pair transition as observed in our photoluminescence spectra." @default.
• W2034866466 created "2016-06-24" @default.
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• W2034866466 date "2011-06-01" @default.
• W2034866466 modified "2023-10-01" @default.
• W2034866466 title "CuGa Se chalcopyrite-related thin films grown by chemical close-spaced vapor transport (CCSVT) for photovoltaic application: Surface- and bulk material properties, oxidation and surface Ge-doping" @default.
• W2034866466 cites W1514173408 @default.
• W2034866466 cites W1565592261 @default.
• W2034866466 cites W1601235747 @default.
• W2034866466 cites W1965707039 @default.
• W2034866466 cites W1965771264 @default.
• W2034866466 cites W1968351688 @default.
• W2034866466 cites W1969625108 @default.
• W2034866466 cites W1974475557 @default.
• W2034866466 cites W1980844845 @default.
• W2034866466 cites W1984306669 @default.
• W2034866466 cites W1984535651 @default.
• W2034866466 cites W1985240449 @default.
• W2034866466 cites W1987043126 @default.
• W2034866466 cites W1987346293 @default.
• W2034866466 cites W1987619865 @default.
• W2034866466 cites W1988038647 @default.
• W2034866466 cites W1990935366 @default.
• W2034866466 cites W1992214743 @default.
• W2034866466 cites W1992489944 @default.
• W2034866466 cites W1992814178 @default.
• W2034866466 cites W1995928867 @default.
• W2034866466 cites W2000616752 @default.
• W2034866466 cites W2002590365 @default.
• W2034866466 cites W2004514584 @default.
• W2034866466 cites W2007200374 @default.
• W2034866466 cites W2008266778 @default.
• W2034866466 cites W2015879388 @default.
• W2034866466 cites W2016103394 @default.
• W2034866466 cites W2016260972 @default.
• W2034866466 cites W2016277920 @default.
• W2034866466 cites W2018089664 @default.
• W2034866466 cites W2018222553 @default.
• W2034866466 cites W2022766859 @default.
• W2034866466 cites W2025480043 @default.
• W2034866466 cites W2027742804 @default.
• W2034866466 cites W2028804128 @default.
• W2034866466 cites W2029359464 @default.
• W2034866466 cites W2029702223 @default.
• W2034866466 cites W2032333995 @default.
• W2034866466 cites W2032401355 @default.
• W2034866466 cites W2034496632 @default.
• W2034866466 cites W2034866466 @default.
• W2034866466 cites W2035688558 @default.
• W2034866466 cites W2037758097 @default.
• W2034866466 cites W2051586599 @default.
• W2034866466 cites W2051935915 @default.
• W2034866466 cites W2052625324 @default.
• W2034866466 cites W2054152536 @default.
• W2034866466 cites W2054563050 @default.
• W2034866466 cites W2057511335 @default.
• W2034866466 cites W2058501893 @default.
• W2034866466 cites W2061109358 @default.
• W2034866466 cites W2064215178 @default.
• W2034866466 cites W2064936896 @default.
• W2034866466 cites W2065164939 @default.
• W2034866466 cites W2067648367 @default.
• W2034866466 cites W2068093798 @default.
• W2034866466 cites W2074701145 @default.
• W2034866466 cites W2075106702 @default.
• W2034866466 cites W2075236723 @default.
• W2034866466 cites W2079111260 @default.
• W2034866466 cites W2081283046 @default.
• W2034866466 cites W2081549302 @default.
• W2034866466 cites W2082886793 @default.
• W2034866466 cites W2085854167 @default.
• W2034866466 cites W2087599743 @default.
• W2034866466 cites W2088082766 @default.
• W2034866466 cites W2092184789 @default.
• W2034866466 cites W2093977510 @default.
• W2034866466 cites W2099350159 @default.
• W2034866466 cites W2106603672 @default.
• W2034866466 cites W2109601433 @default.
• W2034866466 cites W2111937898 @default.

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