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Menzel D, Tejada A, Al-Ashouri A, Levine I, Guerra JA, Rech B, Albrecht S, Korte L. Revisiting the Determination of the Valence Band Maximum and Defect Formation in Halide Perovskites for Solar Cells: Insights from Highly Sensitive Near-UV Photoemission Spectroscopy. ACS APPLIED MATERIALS & INTERFACES 2021; 13:43540-43553. [PMID: 34472345 DOI: 10.1021/acsami.1c10171] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Using advanced near-UV photoemission spectroscopy (PES) in constant final state mode (CFSYS) with a very high dynamic range, we investigate the triple-cation lead halide perovskite Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3 and gain detailed insights into the density of occupied states (DOS) in the valence band and band gap. A valence band model is established which includes the parabolic valence band edge and an exponentially decaying band tail in a single equation. This allows us to precisely determine two valence band maxima (VBM) at different k-vectors in the angle-integrated spectra, where the highest one, resulting from the VBM at the R-point in the Brillouin zone, is found between -1.50 to -1.37 eV relative to the Fermi energy EF. We investigate quantitatively the formation of defect states in the band gap up to EF upon decomposition of the perovskites during sample transfer, storage, and measurements: during near-UV-based PES, the density of defect states saturates at a value that is around 4 orders of magnitude below the density of states at the valence band edge. However, even short air exposure, or 3 h of X-ray illumination, increased their density by almost a factor of six and ∼40, respectively. Upon prolonged storage in vacuum, the formation of a distinct defect peak is observed. Thus, near-UV CFSYS with modeling as shown here is demonstrated as a powerful tool to characterize the valence band and quantify defect states in lead halide perovskites.
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Affiliation(s)
- Dorothee Menzel
- Young Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
| | - Alvaro Tejada
- Young Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
- Departamento de Ciencias, Sección Física, Pontificia Universidad Católica del Perú, Av. Universitaria 1801, 15088 Lima, Peru
| | - Amran Al-Ashouri
- Young Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
| | - Igal Levine
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
| | - Jorge Andres Guerra
- Departamento de Ciencias, Sección Física, Pontificia Universidad Católica del Perú, Av. Universitaria 1801, 15088 Lima, Peru
| | - Bernd Rech
- Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Scientific Management, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
- Faculty IV-Electrical Engineering and Computer Science, Technical University Berlin, Marchstraße 23, 10587 Berlin, Germany
| | - Steve Albrecht
- Young Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
- Faculty IV-Electrical Engineering and Computer Science, Technical University Berlin, Marchstraße 23, 10587 Berlin, Germany
| | - Lars Korte
- Young Investigator Group Perovskite Tandem Solar Cells, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Kekuléstraße 5, 12489 Berlin, Germany
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Mistrik J, Kasap S, Ruda HE, Koughia C, Singh J. Optical Properties of Electronic Materials: Fundamentals and Characterization. SPRINGER HANDBOOK OF ELECTRONIC AND PHOTONIC MATERIALS 2017. [DOI: 10.1007/978-3-319-48933-9_3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Lee W, Choi S, Kim KT, Kang J, Park SK, Kim YH. Determination of Insulator-to-Semiconductor Transition in Sol-Gel Oxide Semiconductors Using Derivative Spectroscopy. MATERIALS 2015; 9:ma9010006. [PMID: 28787803 PMCID: PMC5456563 DOI: 10.3390/ma9010006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 11/17/2022]
Abstract
We report a derivative spectroscopic method for determining insulator-to-semiconductor transition during sol-gel metal-oxide semiconductor formation. When an as-spun sol-gel precursor film is photochemically activated and changes to semiconducting state, the light absorption characteristics of the metal-oxide film is considerable changed particularly in the ultraviolet region. As a result, a peak is generated in the first-order derivatives of light absorption (A′) vs. wavelength (λ) plots, and by tracing the peak center shift and peak intensity, transition from insulating-to-semiconducting state of the film can be monitored. The peak generation and peak center shift are described based on photon-energy-dependent absorption coefficient of metal-oxide films. We discuss detailed analysis method for metal-oxide semiconductor films and its application in thin-film transistor fabrication. We believe this derivative spectroscopy based determination can be beneficial for a non-destructive and a rapid monitoring of the insulator-to-semiconductor transition in sol-gel oxide semiconductor formation.
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Affiliation(s)
- Woobin Lee
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea.
| | - Seungbeom Choi
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea.
| | - Kyung Tae Kim
- School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, Korea.
| | - Jingu Kang
- School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, Korea.
| | - Sung Kyu Park
- School of Electrical and Electronics Engineering, Chung-Ang University, Seoul 06974, Korea.
| | - Yong-Hoon Kim
- SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon 16419, Korea.
- School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 16419, Korea.
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Korte L, Schulze TF, Leendertz C, Schmidt M, Rech B. Band alignment at amorphous/crystalline silicon hetero-interfaces. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/opl.2011.940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTWe present an investigation of the band offsets in amorphous/crystalline silicon heterojunctions (a-Si:H/c-Si) using low energy photoelectron spectroscopy, ellipsometry and surface photovoltage data. For a variation of deposition conditions that lead to changes in hydrogen content and the thereby the a-Si:H band gap by ∼180 meV, we find that mainly the conduction band offset ΔEV varies, while ΔEC stays constant within experimental error. This result can be understood in the framework of charge neutrality (CNL) band lineup theory.
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Queisser HJ, Werner JH. Electrical and Electronic Properties of Grain Boundaries in Silicon. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-106-53] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
ABSTRACTThe electronic states at silicon grain boundaries trap preferentially majority carriers, thus cause a potential barrier impeding current flow. We here summarize measurement techniques for the energy distribution of these grain boundary traps. The analysis reveals band tails due to disorder in the boundary plane as well as interface state continua at midgap. The spatial distribution of trapped charges results in significant electrostatic potential fluctuations which are observable in ac-admittance and noise experiments; the charge fluctuations cause in particular 1/f-like noise. The naive model of dangling bonds to describe grain boundary charges is insufficient, impurity atoms, especially oxygen, play essential roles in determining electronic behavior.
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Klein A, Säuberlich F. Surfaces and Interfaces of Sputter-Deposited ZnO Films. TRANSPARENT CONDUCTIVE ZINC OXIDE 2008. [DOI: 10.1007/978-3-540-73612-7_4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Afanas'ev VV, Stesmans A, Andersson MO. Electron states and microstructure of thin a-C:H layers. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 54:10820-10826. [PMID: 9984878 DOI: 10.1103/physrevb.54.10820] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Barman SR, Shanthi N, Shukla AK, Sarma DD. Order-disorder and electronic transitions in Ag2+ delta S single crystals studied by photoemission spectroscopy. PHYSICAL REVIEW. B, CONDENSED MATTER 1996; 53:3746-3751. [PMID: 9983925 DOI: 10.1103/physrevb.53.3746] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Sebastiani M, Capellini G, Bittencourt C, Evangelisti F. Low-energy yield spectroscopy as a novel technique for determining band offsets: Application to the c-Si(100)/a-Si:H-heterostructure. PHYSICAL REVIEW LETTERS 1995; 75:3352-3355. [PMID: 10059562 DOI: 10.1103/physrevlett.75.3352] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Chahed L, Thèye ML, Fournier D, Roger JP, Boccara AC, Li YM, Turner WA, Paul W. Surface effects in hydrogenated amorphous silicon studied by photothermal-deflection experiments. PHYSICAL REVIEW. B, CONDENSED MATTER 1991; 43:14488-14497. [PMID: 9997340 DOI: 10.1103/physrevb.43.14488] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Aljishi S, Jin S, Ley L, Wagner S. Thermal equilibration of surface defects in hydrogenated amorphous silicon-germanium alloys. PHYSICAL REVIEW LETTERS 1990; 65:629-632. [PMID: 10042972 DOI: 10.1103/physrevlett.65.629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Nithianandam J, Schnatterly SE. Effects of disorder on electronic structures of a-Si:H and a-SiO2. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 40:11786-11791. [PMID: 9991784 DOI: 10.1103/physrevb.40.11786] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Alonso MI, Winer K. Raman spectra of c-Si1-xGex alloys. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:10056-10062. [PMID: 9947783 DOI: 10.1103/physrevb.39.10056] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Oheda H. Instability of the free surface of undoped a-Si:H studied by photoluminescence and electron-spin-resonance measurements. PHYSICAL REVIEW. B, CONDENSED MATTER 1989; 39:10179-10184. [PMID: 9947797 DOI: 10.1103/physrevb.39.10179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Nichols CS, Winer K. Localization of band-edge states in periodic models of a-Si. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:9850-9856. [PMID: 9945807 DOI: 10.1103/physrevb.38.9850] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Winer K, Hirabayashi I, Ley L. Distribution of occupied near-surface band-gap states in a-Si:H. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 38:7680-7693. [PMID: 9945495 DOI: 10.1103/physrevb.38.7680] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Winer K, Hirabayashi I, Ley L. Exponential conduction-band tail in P-doped a-Si:H. PHYSICAL REVIEW LETTERS 1988; 60:2697-2700. [PMID: 10038425 DOI: 10.1103/physrevlett.60.2697] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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Winer K, Ley L. Effects of oxidation on surface band-gap states in a-Si:H. PHYSICAL REVIEW. B, CONDENSED MATTER 1988; 37:8363-8369. [PMID: 9944174 DOI: 10.1103/physrevb.37.8363] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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