Phosphine and tertiarybutylphosphine adsorption on the indium-rich InP (001)-(2×4) surface

Woo, Robyn L.; Das, Ujjal; Cheng, Sha; Chen, G.; Raghavachari, Krishnan; Hicks, Robert F.

doi:10.1016/j.susc.2006.08.014

Cited by 8 publications

(11 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If we compare it with the computed harmonic frequency (2411 cm −1 ), the overestimation is 103 cm −1 . The rough magnitude of this value is consistent with several previous studies27–30 where a uniform shift of 110 cm −1 has been used to correct the computed PH vibrations on indium phosphide surfaces. Thus, it appears that the computed surface frequencies are overestimated significantly more (by about 40 cm −1 ) than their gas phase counterparts.…”

Section: Resultssupporting

confidence: 90%

“…Although many PH frequencies have been experimentally observed on InP, most of their assignments are from our own previous papers 27–30. Thus to avoid circular arguments, we have not included a more detailed comparison between the predicted frequencies and the experimental frequencies in this article.…”

Section: Resultsmentioning

confidence: 99%

“…While the covalent bonds are truncated with hydrogen atoms, the dative bonds at indium are replaced with PH 3 groups to provide an appropriate local bonding environment. Additional information on the electronic distributions of the surfaces and details of the surface modeling can be found in our earlier publications 26–30…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Predicting PH vibrations of gas phase molecules and surface‐adsorbed species using bond length‐frequency correlations

Das

Raghavachari

2008

J Comput Chem

View full text Add to dashboard Cite

The high frequency XH (e.g., X = C, Si) stretching modes in small molecules are only slightly perturbed by other vibrational modes present in the system. The isolated frequencies, in these cases, exhibit a linear relationship with the corresponding bond lengths. Here, we study such a bond length-frequency correlation in the case of PH stretching vibrations for molecules in the gas phase as well as for surface-adsorbed species. Although a high degree of linear correlation is found, there is a small dependence on the local coordination around P, leading to significant deviations in some cases. By a careful analysis, we show that such correlations can be used to predict new surface frequencies without computing the Hessian matrix explicitly.

show abstract

Section: Resultssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Predicting PH vibrations of gas phase molecules and surface‐adsorbed species using bond length‐frequency correlations

Das

Raghavachari

2008

J Comput Chem

View full text Add to dashboard Cite

show abstract

“…29 Low-temperature synchrotron photoemission spectroscopy studies also showed that the H atom of H 2 S or the alkanethiol molecule dissociates at 100−105 K to form S-metal bonds on InP and GaAs(001) surfaces. 7,10 On the basis of previous DFT studies, 38,39 there are two potential adsorption sites for the dissociated H atom; one site is on the 1P atom (H−1P bond) and the other is located on the edge Ga−Ga dimers (Ga−H−Ga bond). The location of the center of the bright protrusion in Figure 3a is consistent with the S atom when the propanethiolate adsorbate is bound to the edge Ga atom (3Ga or 4Ga in Figure 1d).…”

Section: Resultsmentioning

confidence: 99%

“…29 Low-temperature synchrotron photoemission spectroscopy studies also showed that the H atom of H 2 S or the alkanethiol molecule dissociates at 100 ~ 105 K to form Smetal bonds on InP and GaAs(001) surfaces. 7,10 Based on previous DFT studies, 38,39 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 11 molecule and the surface atom is maintained. Based on a van der Waals corrected DFT method (PBE-D3), the rotational barrier over the lowest three conformations of the propanethiolate bound to the edge Ga atom is 15 meV, which can be overcome at the measurement temperature of 298 K. The stark difference in the apparent shapes for feature A and B in the STM images is, therefore, proposed to result from rotation of the Ga-S bond.…”

Section: Structure Analysis By Stm and Dft Calculationsmentioning

confidence: 99%

Probing Surface Chemistry at an Atomic Level: Decomposition of 1-Propanethiol on GaP(001) (2 × 4) Investigated by STM, XPS, and DFT

et al. 2019

View full text Add to dashboard Cite

The adsorption and decomposition mechanisms for 1-propanethiol on a Ga-rich GaP(001)(2×4) surface are investigated at an atomic level using scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations.Using a combination of experimental and theoretical tools, we probe the detailed structures and energetics of a series of reaction intermediates in the thermal decomposition pathway from 130 to 773 K. At 130 K, the propanethiolate adsorbates are observed at the edge gallium sites, with the thiolate-Ga bonding configuration maintained up to 473 K. Further decomposition produces two new surface features, Ga-S-Ga and P-propyl species at 573 K. Finally, S-induced (1×1) and (2×1) reconstructions are observed at 673 ~ 773 K, which are reportedly associated with arrays of surface Ga-S-Ga bonds and subsurface diffusion of S. To understand the observed site-selectivity on the hydrogen dissociation of the thiol molecule at 130 K, the two most likely dissociation pathways (Ga-P vs. Ga-Ga dimer sites) are investigated using DFT Gibbs energy calculations. While the theory predicts the kinetic advantage for the dissociation reaction occurring on the Ga-P dimer (Lewis acid-base combination), we only observed dissociation products on the Ga-Ga dimer (Lewis acid). The DFT calculations clarify that the reversible thiolate diffusion along the Ga dimer row prevents recombinative desorption, which is probable on the Ga-P dimer. Together with experimental and theoretical results, we suggest a thermal decomposition mechanism for the thiol molecule with atomic-level structural details.

show abstract

Surface Chemistry of tert‐Butylphosphine (TBP) on Si(001) in the Nucleation Phase of Thin‐Film Growth

Stegmüller

Werner

Reutzel

et al. 2016

Chemistry A European J

View full text Add to dashboard Cite

We combine density functional theory calculations and scanning tunneling microscopy investigations to identify the relevant chemical species and reactions in the nucleation phase of chemical vapor deposition. tert-Butylphosphine (TBP) was deposited on a silicon substrate under conditions typical for surface functionalization and growth of semiconductor materials. On the activated hydrogen-covered surface H/Si(001) it forms a strong covalent P-Si bond without loss of the tert-butyl group. Calculations show that site preference for multiple adsorption of TBP is influenced by steric repulsion of the adsorbate's bulky substituent. STM imaging furthermore revealed an anisotropic distribution of TBP with a preference for adsorption perpendicular to the surface dimer rows. The adsorption patterns found can be understood by a mechanism invoking stabilization of surface hydrogen vacancies through electron donation by an adsorbate. The now improved understanding of nucleation in thin-film growth may help to optimize molecular precursors and experimental conditions and will ultimately lead to higher quality materials.

show abstract

Phosphine and tertiarybutylphosphine adsorption on the indium-rich InP (001)-(2×4) surface

Cited by 8 publications

References 19 publications

Predicting PH vibrations of gas phase molecules and surface‐adsorbed species using bond length‐frequency correlations

Predicting PH vibrations of gas phase molecules and surface‐adsorbed species using bond length‐frequency correlations

Probing Surface Chemistry at an Atomic Level: Decomposition of 1-Propanethiol on GaP(001) (2 × 4) Investigated by STM, XPS, and DFT

Surface Chemistry of tert‐Butylphosphine (TBP) on Si(001) in the Nucleation Phase of Thin‐Film Growth

Contact Info

Product

Resources

About