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Ekar J, Panjan P, Drev S, Kovač J. ToF-SIMS Depth Profiling of Metal, Metal Oxide, and Alloy Multilayers in Atmospheres of H 2, C 2H 2, CO, and O 2. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:31-44. [PMID: 34936371 PMCID: PMC8739835 DOI: 10.1021/jasms.1c00218] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 12/08/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
The influence of the flooding gas during ToF-SIMS depth profiling was studied to reduce the matrix effect and improve the quality of the depth profiles. The profiles were measured on three multilayered samples prepared by PVD. They were composed of metal, metal oxide, and alloy layers. Dual-beam depth profiling was performed with 1 keV Cs+ and 1 keV O2+ sputter beams and analyzed with a Bi+ primary beam. The novelty of this work was the application of H2, C2H2, CO, and O2 atmospheres during SIMS depth profiling. Negative cluster secondary ions, formed from sputtered metals/metal oxides and the flooding gases, were analyzed. A systematic comparison and evaluation of the ToF-SIMS depth profiles were performed regarding the matrix effect, ionization probability, chemical sensitivity, sputtering rate, and depth resolution. We found that depth profiling in the C2H2, CO, and O2 atmospheres has some advantages over UHV depth profiling, but it still lacks some of the information needed for an unambiguous determination of multilayered structures. The ToF-SIMS depth profiles were significantly improved during H2 flooding in terms of matrix-effect reduction. The structures of all the samples were clearly resolved while measuring the intensity of the MnHm-, MnOm-, MnOmH-, and Mn- cluster secondary ions. A further decrease in the matrix effect was obtained by normalization of the measured signals. The use of H2 is proposed for the depth profiling of metal/metal oxide multilayers and alloys.
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Affiliation(s)
- Jernej Ekar
- Jožef
Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Jožef
Stefan International Postgraduate School, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Peter Panjan
- Jožef
Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Sandra Drev
- Jožef
Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
- Center
for Electron Microscopy and Microanalysis, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
| | - Janez Kovač
- Jožef
Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia
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2
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Yu X, Yu J, Zhou Y, Zhang Y, Wang J, Evans JE, Yu XY, Wang XL, Zhu Z. An investigation of the beam damage effect on in situ liquid secondary ion mass spectrometry analysis. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:2035-2042. [PMID: 28884926 DOI: 10.1002/rcm.7983] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 09/02/2017] [Accepted: 09/02/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE During in situ liquid secondary ion mass spectrometry (SIMS) analysis, the primary ion beam is normally scanned on a very small area to collect signals with high ion doses (1014 to 1016 ions/cm2 ). As a result, beam damage may become a concern when compared with the static limit of SIMS analysis, in which the dose is normally less than 1012 ions/cm2 . Therefore, a comparison of ion yields in in situ liquid SIMS analysis versus traditional static SIMS analysis of corresponding dry samples is of great interest. METHODS In this study, a dipalmitoylphosphatidylcholine (DPPC) liposome solution was used as a model system. Both liquid sample and dry sample were examined. Secondary ion yields using three primary ion species (Bi+ , Bi3+ and Bi3++ ) with various beam currents were investigated. RESULTS Usable ion yields for both positive and negative characteristic signals (including molecular ions and characteristic fragment ions) were achievable based on optimized experimental conditions for in situ liquid SIMS analysis. The ion yield of the key DPPC molecular ion was comparable to that of traditional static SIMS, and unexpected low fragmentation was observed. The flexible structure of the liquid plays an important role for these observations. CONCLUSIONS Therefore, beam damage may not be a concern in in situ liquid SIMS analysis if proper experimental conditions are used.
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Affiliation(s)
- Xiaofei Yu
- School of Physics, State Key Laboratory of Crystal Materials & Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan, 250100, China
- W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Jiachao Yu
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Yufan Zhou
- School of Physics, State Key Laboratory of Crystal Materials & Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan, 250100, China
- W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Yanyan Zhang
- W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Jungang Wang
- W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - James E Evans
- W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Xiao-Ying Yu
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Xue-Lin Wang
- School of Physics, State Key Laboratory of Crystal Materials & Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan, 250100, China
| | - Zihua Zhu
- W. R. Wiley Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
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3
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Zhou Y, Yao J, Ding Y, Yu J, Hua X, Evans JE, Yu X, Lao DB, Heldebrant DJ, Nune SK, Cao B, Bowden ME, Yu XY, Wang XL, Zhu Z. Improving the Molecular Ion Signal Intensity for In Situ Liquid SIMS Analysis. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:2006-2013. [PMID: 27600576 DOI: 10.1007/s13361-016-1478-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Revised: 08/08/2016] [Accepted: 08/10/2016] [Indexed: 06/06/2023]
Abstract
In situ liquid secondary ion mass spectrometry (SIMS) enabled by system for analysis at the liquid vacuum interface (SALVI) has proven to be a promising new tool to provide molecular information at solid-liquid and liquid-vacuum interfaces. However, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. In addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. These two drawbacks have been the biggest obstacle towards practical use of this new analytical approach. In this study, we report that strong and reliable positive and negative molecular signals are achievable after optimizing the SIMS experimental conditions. Four model systems, including a 1,8-diazabicycloundec-7-ene (DBU)-base switchable ionic liquid, a live Shewanella oneidensis biofilm, a hydrated mammalian epithelia cell, and an electrolyte popularly used in Li ion batteries were studied. A signal enhancement of about two orders of magnitude was obtained in comparison with non-optimized conditions. Therefore, molecular ion signal intensity has become very acceptable for use of in situ liquid SIMS to study solid-liquid and liquid-vacuum interfaces. Graphical Abstract ᅟ.
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Affiliation(s)
- Yufan Zhou
- School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan, 250100, China
- W. R. Wiley Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Juan Yao
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Yuanzhao Ding
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- School of Civil and Environmental Engineering and Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Jiachao Yu
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Xin Hua
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - James E Evans
- W. R. Wiley Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Xiaofei Yu
- School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan, 250100, China
- W. R. Wiley Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - David B Lao
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - David J Heldebrant
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Satish K Nune
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Bin Cao
- School of Civil and Environmental Engineering and Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Mark E Bowden
- W. R. Wiley Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Xiao-Ying Yu
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
| | - Xue-Lin Wang
- School of Physics, State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation (MOE), Shandong University, Jinan, 250100, China.
| | - Zihua Zhu
- W. R. Wiley Environmental Molecular Sciences Laboratory, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
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4
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Chu YH, Liao HY, Lin KY, Chang HY, Kao WL, Kuo DY, You YW, Chu KJ, Wu CY, Shyue JJ. Improvement of the gas cluster ion beam-(GCIB)-based molecular secondary ion mass spectroscopy (SIMS) depth profile with O2(+) cosputtering. Analyst 2016; 141:2523-33. [PMID: 27000483 DOI: 10.1039/c5an02677f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Over the last decade, cluster ion beams have displayed their capability to analyze organic materials and biological specimens. Compared with atomic ion beams, cluster ion beams non-linearly enhance the sputter yield, suppress damage accumulation and generate high mass fragments during sputtering. These properties allow successful Secondary Ion Mass Spectroscopy (SIMS) analysis of soft materials beyond the static limit. Because the intensity of high mass molecular ions is intrinsically low, enhancing the intensity of these secondary ions while preserving the sample in its original state is the key to highly sensitive molecular depth profiles. In this work, bulk poly(ethylene terephthalate) (PET) was used as a model material and analyzed using Time-of-Flight SIMS (ToF-SIMS) with a pulsed Bi3(2+) primary ion. The optimized hardware of a 10 kV Ar2500(+) Gas Cluster Ion Beam (GCIB) with a low kinetic energy (200-500 V) oxygen ion (O2(+)) as a cosputter beam was employed for generating depth profiles and for examining the effect of beam parameters. The results were then quantitatively analyzed using an established erosion model. It was found that the ion intensity of the PET monomer ([M + H](+)) and its large molecular fragment ([M - C2H4O + H](+)) steadily declined during single GCIB sputtering, with distortion of the distribution information. However, under an optimized GCIB-O2(+) cosputter, the secondary ion intensity quickly reached a steady state and retained >95% intensity with respect to the pristine surface, although the damage cross-section was larger than that of single GCIB sputtering. This improvement was due to the oxidation of molecules and the formation of -OH groups that serve as proton donors to particles emitted from the surface. As a result, the ionization yield was enhanced and damage to the chemical structure was masked. Although O2(+) is known to alter the chemical structure and cause damage accumulation, the concurrently used GCIB could sufficiently remove the surface layer and allow the damage to be masked by the enhanced ionization yield when the ion-solid interaction volume was kept shallow with a low O2(+) energy. This low O2(+) energy (200 V) cosputtering also produced a smoother surface than a single GCIB. Because the oxidized species were produced by O2(+) and removed by GCIB simultaneously, a sufficiently high O2(+) current density was required to produce adequate enhancements. Therefore, it was found that 10 kV with 2 × 10(-6) A per cm(2) Ar2500(+) and 200 V with 3.2 × 10(-4) A per cm(2) O2(+) produced the best profile.
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Affiliation(s)
- Yi-Hsuan Chu
- Department of Materials Science and Engineering, National Taiwan University, Taipei, Taiwan.
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5
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Liao HY, Tsai MH, Kao WL, Kuo DY, Shyue JJ. Effects of the temperature and beam parameters on depth profiles in X-ray photoelectron spectrometry and secondary ion mass spectrometry under C60+–Ar+ cosputtering. Anal Chim Acta 2014; 852:129-36. [DOI: 10.1016/j.aca.2014.08.044] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 08/20/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
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6
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Liao HY, Lin KY, Kao WL, Chang HY, Huang CC, Shyue JJ. Enhancing the Sensitivity of Molecular Secondary Ion Mass Spectrometry with C60+-O2+ Cosputtering. Anal Chem 2013; 85:3781-8. [DOI: 10.1021/ac400214t] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hua-Yang Liao
- Research Center for Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Kang-Yi Lin
- Research Center for Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Wei-Lun Kao
- Research Center for Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Hsun-Yun Chang
- Research Center for Applied
Science, Academia Sinica, Tapei 115, Taiwan
- Nanoscience
and Technology Program,
Taiwan International Graduate Program, Academia Sinica, Taipei 115, Taiwan
- Department
of Engineering and
System Science, National Tsing Hua University, Hsin-Chu, 300, Taiwan
| | - Chih-Chieh Huang
- Department of Materials Science
and Engineering, Nation Taiwan University, Taipei 106, Taiwan
| | - Jing-Jong Shyue
- Research Center for Applied
Science, Academia Sinica, Tapei 115, Taiwan
- Department of Materials Science
and Engineering, Nation Taiwan University, Taipei 106, Taiwan
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7
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Thompson RJ, Fearn S, Tan KJ, Cramer HG, Kloc CL, Curson NJ, Mitrofanov O. Revealing surface oxidation on the organic semi-conducting single crystal rubrene with time of flight secondary ion mass spectroscopy. Phys Chem Chem Phys 2013; 15:5202-7. [DOI: 10.1039/c3cp50310k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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8
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Liao HY, Tsai MH, Chang HY, You YW, Huang CC, Shyue JJ. Effect of Cosputtering and Sample Rotation on Improving C60+ Depth Profiling of Materials. Anal Chem 2012; 84:9318-23. [DOI: 10.1021/ac3020824] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Hua-Yang Liao
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Meng-Hung Tsai
- Department of Materials Science
and Engineering, Nation Taiwan University, Taipei 106, Taiwan
| | - Hsun-Yun Chang
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Yun-Wen You
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Chih-Chieh Huang
- Department of Materials Science
and Engineering, Nation Taiwan University, Taipei 106, Taiwan
| | - Jing-Jong Shyue
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
- Department of Materials Science
and Engineering, Nation Taiwan University, Taipei 106, Taiwan
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9
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Liao HY, Tsai MH, You YW, Chang HY, Huang CC, Shyue JJ. Dramatically Enhanced Oxygen Uptake and Ionization Yield of Positive Secondary Ions with C60+ Sputtering. Anal Chem 2012; 84:3355-61. [DOI: 10.1021/ac300147g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hua-Yang Liao
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Meng-Hung Tsai
- Department
of Materials Science and Engineering, Nation Taiwan University, Taipei 106, Taiwan
| | - Yun-Wen You
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Hsun-Yun Chang
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
| | - Chih-Chieh Huang
- Department
of Materials Science and Engineering, Nation Taiwan University, Taipei 106, Taiwan
| | - Jing-Jong Shyue
- Research Center for
Applied
Science, Academia Sinica, Tapei 115, Taiwan
- Department
of Materials Science and Engineering, Nation Taiwan University, Taipei 106, Taiwan
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10
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Zhu Z, Shutthanandan V. Are cluster ion analysis beams good choices for hydrogen depth profiling using time-of-flight secondary ion mass spectrometry? SURF INTERFACE ANAL 2011. [DOI: 10.1002/sia.3776] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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11
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Lin WC, Liu CP, Kuo CH, Chang HY, Chang CJ, Hsieh TH, Lee SH, You YW, Kao WL, Yen GJ, Huang CC, Shyue JJ. The role of the auxiliary atomic ion beam in C60+–Ar+co-sputtering. Analyst 2011; 136:941-6. [DOI: 10.1039/c0an00642d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Wehbe N, Houssiau L. Comparative Study of the Usefulness of Low Energy Cs+, Xe+, and O2+ Ions for Depth Profiling Amino-Acid and Sugar Films. Anal Chem 2010; 82:10052-9. [DOI: 10.1021/ac101696c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Nimer Wehbe
- Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), 61, rue de Bruxelles, B-5000 Namur, Belgium
| | - Laurent Houssiau
- Research Centre in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), 61, rue de Bruxelles, B-5000 Namur, Belgium
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13
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Zhu Z, Shutthanandan V, Nachimuthu P. Using C60
+
sputtering to improve detection limit of nitrogen in zinc oxide. SURF INTERFACE ANAL 2010. [DOI: 10.1002/sia.3414] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Yu BY, Lin WC, Wang WB, Iida SI, Chen SZ, Liu CY, Kuo CH, Lee SH, Kao WL, Yen GJ, You YW, Liu CP, Jou JH, Shyue JJ. Effect of fabrication parameters on three-dimensional nanostructures of bulk heterojunctions imaged by high-resolution scanning ToF-SIMS. ACS NANO 2010; 4:833-840. [PMID: 20099877 DOI: 10.1021/nn9014449] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Solution processable fullerene and copolymer bulk heterojunctions are widely used as the active layers of solar cells. In this work, scanning time-of-flight secondary ion mass spectrometry (ToF-SIMS) is used to examine the distribution of [6,6]phenyl-C61-butyric acid methyl ester (PCBM) and regio-regular poly(3-hexylthiophene) (rrP3HT) that forms the bulk heterojunction. The planar phase separation of P3HT:PCBM is observed by ToF-SIMS imaging. The depth profile of the fragment distribution that reflects the molecular distribution is achieved by low energy Cs(+) ion sputtering. The depth profile clearly shows a vertical phase separation of P3HT:PCBM before annealing, and hence, the inverted device architecture is beneficial. After annealing, the phase segregation is suppressed, and the device efficiency is dramatically enhanced with a normal device structure. The 3D image is obtained by stacking the 2D ToF-SIMS images acquired at different sputtering times, and 50 nm features are clearly differentiated. The whole imaging process requires less than 2 h, making it both rapid and versatile.
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Affiliation(s)
- Bang-Ying Yu
- Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan
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