Gao Ga2O3 Ga2S3 Ga2(SO4)3 GaN  GaP  GaSb GaF3 LiGaO2   GaInAl GaInAs AlGaAs CuGa CuInGa   Basic 

XPS Spectra
Gallium (Ga) Compounds
The XPS Spectra section provides raw and processed survey spectra, chemical state spectra, BE values, FWHM values, and overlays of key spectra.
Atom% values from surveys are based on sample, as received, and Scofield cross-sections. Atom% values are corrected for IMFP and PE.
Peak-fits are guides for practical, real-world applications. Peak-fits are not fully optimized or designed to test any theory.

Gallium Oxide  (Ga2O3)
Survey, Peak-fits, BEs, FWHMs, and Peak Labels

→  Periodic Table   → Six (6) BE Tables
Survey Spectrum from Ga2O3
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag (3d5/2) FWHM = 1.3 eV
→  Periodic Table  → Six (6) BE Tables
Ga (3d) Spectrum from Ga2O3 – Raw
Fresh exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 Ga (3d) Spectrum from Ga2O3 – Peak-Fit
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV

→  Periodic Table  → Six (6) BE Tables
Ga (2p) Spectrum from Ga2O3 – Raw
Fresh exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 Ga (2p3/2) Spectrum from Ga2O3 – Peak-fit
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV
 
→  Periodic Table  → Six (6) BE Tables
Ga (3s) Spectrum from Ga2O3 – Raw
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 Ga (3s) Spectrum from Ga2O3 – Peak-fit
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV


→  Periodic Table  → Six (6) BE Tables
O (1s) Spectrum from Ga2O3 – Raw 
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 O (1s) Spectrum from Ga2O3 – Peak-fit
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV
 
→  Periodic Table  → Six (6) BE Tables
C (1s) Spectrum from Ga2O3 – Peak-fit – As measured 
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 280.69 eV, Ag FWHM = 0.75 eV		 C (1s) Spectrum from Ga2O3 – Peak-Fit – Corrected
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV
→  Periodic Table  → Six (6) BE Tables
Ga (3p) Spectrum from Ga2O3 – Raw
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 Ga (3p) Spectrum from Ga2O3 – peak-fit
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV
→  Periodic Table  → Six (6) BE Tables
Ga Auger Spectrum from Ga2O3 – Raw
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 Valence Band Signals from Ga2O3 – Raw
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV

 
Overlays
→  Periodic Table  → Six (6) BE Tables
Valence Band Spectra – Overlay of Gao and Ga2O3
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 Ga (3d) Spectra – Overlay of Energy Loss from Gao and Ga2O3
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV
→  Periodic Table  → Six (6) BE Tables
Ga (3d) Spectra – Overlay of Ga, Ga2O3 and Ga2S3
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV		 Ga (3d) Spectra – Overlay of Gao, GaAs, and Ga2O3
Freshly exposed bulk, Flood gun is ON, C (1s) BE = 285.0 eV, Ag FWHM = 0.75 eV

End-of-spectra

Price to purchase complete data-sets (5-8 spectra in one data-set):
Raw spectra – VAMAS ASCII format ($6)
Raw spectra – SDP binary format ($5)
SDP v9 – $145 (5 yr license)

 

 

 

Transmission Function Tests
 

December 2015 – Transmission Function of Thermo K-Alpha Plus
→  Periodic Table 
Survey Spectra of Ion Etched Copper (Cr), PEs = 50, 100, 150 and 200 eV
→  Periodic Table 
March 2016 – Transmission Function of Thermo K-Alpha Plus 
 
Survey Spectra of Ion Etched Copper (Cr), PEs = 100, 150 and 200 eV
→  Periodic Table  
August 2019 – Transmission Function of Thermo K-Alpha Plus
 
Survey Spectra of HOPG (C), PEs = 20, 50, 100 and 200 eV
→  Periodic Table  
January 2022 – Transmission Function of Thermo K-Alpha Plus
Survey Spectra of Ion Etched Copper (Cr), PEs = 100, 120, 140, 160, 180 and 200 eV

 

Six (6) Chemical State Tables of Ga (2p) BEs

 

  • The XPS Library Spectra-Base
  • PHI Handbook
  • Thermo-Scientific Website
  • XPSfitting Website
  • Techdb Website
  • NIST Website

→  Periodic Table 

 

 

Notes of Caution when using Published BEs and BE Tables from Insulators and Conductors:

  • Accuracy of Published BEs
    • The accuracy depends on the calibration BEs used to calibrate the energy scale of the instrument.  Cu (2p3/2) BE can vary from 932.2 to 932.8 eV for old publications
    • Different authors use different BEs for the C (1s) BE of the hydrocarbons found in adventitious carbon that appears on all materials and samples.  From 284.2 to 285.3 eV
    • The accuracy depends on when the authors last checked or adjusted their energy scale to produce the expected calibration BEs
  • There are uncertainties and error ranges in nearly all BEs 
    • Flood guns
  • Worldwide Differences in Energy Scale Calibrations
    • For various reasons authors still use older energy scale calibrations
    • Some authors still adjust their energy scale so Cu (2p3/2) appears at 932.2 eV or 932.8 eV because this is what the maker taught them
    • This range causes BEs in the higher BE end to be larger than expected
    • This variation increases significantly above 600 eV BE
  • Charge Compensation
    • Samples that behave as true insulators normally require the use of a charge neutralizer (electron flood gun with or without Ar+ ions) so that the measured chemical state spectra can be produced without peak-shape distortions or sloping tails on the low BE side of the peak envelop.
    • Floating all samples (conductive, semi-conductive, and non-conductive) and always using the electron flood gun is considered to produce more reliable BEs and is recommended.
  • Charge Referencing Methods for Insulators
    • Charge referencing is a common method, but it can produce results that are less reliable.
    • When an electron flood gun is used, the BE scale will usually shift to lower BE values by 0.01 to 5.0 eV depending on your voltage setting. Normally, to correct for this flood gun induced shift, the BE of the hydrocarbon C (1s) peak maximum from adventitious carbon is used to correct for the charge induced shift.
    • The hydrocarbon peak is normally the largest peak at the lowest BE.
    • Depending on your preference or training, the C (1s) BE assigned to this hydrocarbon peak varies from 284.8 to 285.0 eV.  Other BEs can be as low as 284.2 eV or as high as 285.3 eV
    • Native oxides that still show the pure metal can suffer differential charging that causes the C (1s) and the O (1s) and the Metal Oxide BE to be larger
    • When using the electron flood gun, the instrument operator should adjust the voltage and the XY position of the electron flood gun to produce peaks from a strong XPS signGa (eg O (1s) or C (1s) having the most narrow FWHM and the lowest experimentally measured BE.

→  Periodic Table 

Table #1

Ga (2p) Chemical State BEs from:  “The XPS Library Spectra-Base”

C (1s) BE = 285.0 eV for TXL BEs
and C (1s) BE = 284.8 eV for NIST BEs

Element Atomic # Compound As-Measured by TXL or NIST Average BE Largest BE Hydrocarbon C (1s) BE  Source
Al 13 Al – element 72.9 eV 285.0 The XPS Library
Al 13 AlGaAs 74.1 eV 285.0 The XPS Library
Al 13 Al2O3 (N*3) 74.3 eV 74.7 eV  284.8 Avg BE – NIST
Al 13 Al-N 74.3 eV 285.0 The XPS Library
Al 13 Pyrope 74.4 eV 285.0 The XPS Library
Al 13 Mica 74.5 eV 285.0 The XPS Library
Al 13 Al2SiO5 74.7 eV 285.0 The XPS Library
Al 13 Al2(SO4)3 (N*1) 74.9 eV 284.8 Avg BE – NIST
Al 13 LiAlSi2O6 75.3 eV 285.0 The XPS Library
Al 13 Al2O3/Al 75.4 eV 75.9 eV 285.0 The XPS Library
Al 13 Al2O3-TiC 75.4 eV 285.0 The XPS Library
Al 13 Al2O3/Ga (N*16) 75.6 eV 75.8 eV 284.8 Avg BE – NIST
Al 13 Al-OOH 75.7 eV 285.0 The XPS Library
Al 13 Al(OH)3 76.2 eV 285.0 The XPS Library
Al 13 Al-F3 77.0 eV 285.0 The XPS Library
Al 13 Al-Br3 285.0 The XPS Library
Al 13 Al-SO4 76.1 eV 285.0 The XPS Library

Charge Referencing

  • (N*number) identifies the number of NIST BEs that were averaged to produce the BE in the middle column.
  • Binding Energy Scale Calibration expects Cu (2p3/2) BE = 932.62 eV and Au (4f7/2) BE = 83.98 eV.  BE (eV) Uncertainty Range:  +/- 0.2 eV
  • Charge Referencing of insulators is defined such that the Adventitious Hydrocarbon C (SO) BE (eV) = 285.0 eV.  NIST uses C (1s) BE = 284.8 eV 
  • Note:   Ion etching removes adventitious carbon, implants Ar (+), changes conductivity of surface, and degrades chemistry of various chemical states.
  • Note:  Ion Etching changes BE of C (1s) hydrocarbon peak.
  • TXL – abbreviation for: “The XPS Library” (https://xpslibrary.com).  NIST:  National Institute for Science and Technology (in USA)

 →  Periodic Table 

Table #2

Ga (2p) Chemical State BEs from:  “PHI Handbook”

C (1s) BE = 284.8 eV

Copyright ©:  Ulvac-PHI

Table #3

Ga (2p) Chemical State BEs from:  “Thermo-Scientific” Website

C (1s) BE = 284.8 eV

Chemical State Binding Energy – Ga (2p)
Al metal 72.6 eV
 Aluminosilicate 74.4 eV
 Al oxide 74.6 eV
Al oxide on Al foil 75.6 eV

Copyright ©:  Thermo Scientific website

Table #4

Ga (2p) Chemical State BEs from:  “XPSfitting” Website

Chemical State BE Table derived by Averaging BEs in the NIST XPS database of BEs
C (1s) BE = 284.8 eV

Copyright ©:  Mark Beisinger

Table #5

Ga (2p) Chemical State BEs from:  “Techdb.podzone.net” Website

XPS Spectra – Chemical Shift | Binding Energy
C (1s) BE = 284.6 eV

Element Level Compound B.E. (eV) min max
Al 2p Al 72.8 ±0.3 72.5 ～ 73.0
Al 2p AlAs 73.6 ±0.3 73.3 ～ 73.9
Al 2p AlGaAs 73.7 ±0.4 73.3 ～ 74.0
Al 2p Al2O3, alpha 73.9 ±0.3 73.6 ～ 74.2
Al 2p Al2O3, gamma 74.0 ±0.3 73.7 ～ 74.3
Al 2p Al2O3, sapphire 74.2 ±0.3 73.9 ～ 74.5
Al 2p AlOOH, boehmite 74.3 ±0.3 74.0 ～ 74.6
Al 2p Oxides 74.5 ±0.3 74.2 ～ 74.8
Al 2p Halides 75.4 ±0.9 74.5 ～ 76.3
Al 2p LiAlH4 75.6 ±0.4 75.2 ～ 76.0
Al 2p AlF3 76.4 ±0.4 76.0 ～ 76.7

Histograms of NIST BEs from Ga (2p)
NIST Database defines Adventitious Hydrocarbon C (1s) BE = 284.8 eV for all insulators.

Histogram indicates Ga (2p) BE = 72.9 eV for Aluminum MetGa (Al)
based on 15 literature BEs		 Histogram indicates Ga (2p) BE = 75.7 eV for Native Aluminum Oxide on top of Aluminum based on 18 literature BEs

Table #6

NIST Database of Ga (2p) Binding Energies

NIST Standard Reference Database 20, Version 4.1

Data compiled and evaluated
by
Alexander V. Naumkin, Anna Kraut-Vass, Stephen W. Gaarenstroom, and Cedric J. Powell
©2012 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.