Basic XPS Information Section

The Basic XPS Information Section provides fundamental XPS spectra, BE values, FWHM values, BE tables, overlays of key spectra, histograms and a table of XPS parameters.
The Advanced XPS Information Section is a collection of additional spectra, overlays of spectra, peak-fit advice, data collection guidance, material info,
common contaminants, degradation during analysis, auto-oxidation, gas capture study, valence band spectra, Auger spectra, and more.
Published literature references, and website links are summarized at the end of the advanced section.
→  Periodic Table – HomePage                    XPS Database of Polymers                    → Six (6) BE Tables  


Indium (In)

 

Cadmoindite – CdIn2S4 Indium – Ino Ramdohrite – Pb5.9Fe0.1Mn0.1In0.1Cd0.2Ag2.8Sb10.8S24

 

  Page Index
  • Expert Knowledge & Explanations


Indium (Ino) Metal

Peak-fits, BEs, FWHMs, and Peak Labels

  .
Indium (Ino) Metal
In (3d) Spectrum – raw spectrum
ion etched clean		 Indium (Ino) Metal
Peak-fit of In (3d5/2) Spectrum
(w/o asymm)
→  Periodic Table – HomePage  
Indium (Ino) Metal
In (3d) Spectrum – extended range 
 Indium (Ino) Metal
Peak-fit of In (3d5/2) Spectrum (w asymm)

 
Indium (Ino) Metal
In (4s) Spectrum		 Indium (Ino) Metal
In (4p) Spectrum
 

Survey Spectrum of Indium (Ino) Metal
with Peaks Integrated, Assigned and Labelled

 

→  Periodic Table 

XPS Signals for Indium, (Ino) Metal

Spin-Orbit Term,  BE (eV) Value, and Scofield σ for Aluminum Kα X-rays (1486 eV, 8.33 Ang)

Overlaps Spin-Orbit Term BE (eV) Value Scofield σ from 1486 eV X-rays IMFP (TPP-2M) in Å
  In (3s) 827 3.16 18.6
Fe (2p) overlaps In (3p1/2) 703 4.40 21.8
  In (3p3/2) 665 8.93 21.8
Ti (2p) overlaps In (3d3/2) 451.3 9.22 26.0
Pb (4d) overlaps In (3d5/2) 443.75 13.32 26.0
Al (2s) & Cu (3s) overlap In (4s) ~123 0.742 32.1
Al (2p) & Cu (3p) overlap In (4p) 78 2.45 32.9

σ:  abbreviation for the term Scofield Photoionization Cross-Section which are used with IMFP and TF to generate RSFs and atom% quantitation

Energy Loss Peaks

Auger Peaks

  
Expected Bandgap for In2O3:  3-3.5 eV
Work Function for In:  xx eV

*Scofield Cross-Section (σ) for C (1s) = 1.0

→  Periodic Table 

 

In (4s) and (4p) Spectra from Ino Metal
Fresh exposed bulk produced by extensive Ar+ ion etching
(Study of One Electron Breakdown)

In (4s) In (4p)

 

 

Valence Band Spectrum from Indium, Ino Metal
 Fresh exposed bulk produced by extensive Ar+ ion etching

 

Plasmon Peaks from Ino Metal
 Fresh exposed bulk produced by extensive Ar+ ion etching

In (3d) – Extended Range Spectrum In (3d) – Extended Range Spectrum – Vertically Zoomed
→  Periodic Table 

 

In (MNN) Auger Peaks from Ino Metal
 Fresh exposed bulk produced by extensive Ar+ ion etching
Ino Metal – main Auger peak Ino Metal – full Auger range
 

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Artefacts Caused by Argon Ion Etching

Indium Carbide(s)

can form when ion etched Reactive Metal Surfaces capture
Residual UHV Gases (CO, H2O, CH4 etc)

Argon Trapped in Ino

can form when Argon Ions are used
to removed surface contamination
na na

 

Side-by-Side Comparison of
In Native Oxide & Indium Oxide (In2O3)
Peak-fits, BEs, FWHMs, and Peak Labels
In Native Oxide In2O3
In (3d5/2) from In Native Oxide
Flood Gun OFF
As-Measured, C (1s) at 285.4 eV 		 In (3d5/2) In2O3 – pressed powder
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

The peak at 443.8 eV is the pure metal.  The peak at 444.4 eV is In2O3.
The peak at 445.3 eV is In(OH)3

The peak at 444.2 eV is from In2O3.
The peak at 445.1 eV is from In(OH)3
→  Periodic Table 
  . 
In Native Oxide In2O3
C (1s) from In Native Oxide
As-Measured, C (1s) at 285.4 eV
Flood Gun OFF

C (1s) from In2O3 – pressed powder
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

 
→  Periodic Table 
  . 
In Native Oxide In2O3
O (1s) from In Native Oxide
As-Measured, C (1s) at 285.4 eV
Flood Gun OFF

O (1s) from In2O3 – pressed powder
Flood Gun ON
Charge Referenced to C (1s) at 285.0 eV

 
NOTES:  The peak at 530.2 eV is from In2O3.
The peak at 532.1 eV is attributed to In(OH)3.		 NOTES:  The peak at 529.8 eV is from In2O3.
The peak at 532.1 eV is attributed to In(OH)3.
→  Periodic Table

 
 

 

Survey Spectrum of Indium (In) Native Oxide
with Peaks Integrated, Assigned and Labelled

 

→  Periodic Table 

 

 

Survey Spectrum of Indium Oxide (In2O3)
with Peaks Integrated, Assigned and Labelled


→  Periodic Table  

 

Overlays of In (3d) Spectra for
In Native Oxide and Indium Oxide (In2O3)

Caution: BEs from Grounded Native Oxides can be Misleading if Flood Gun is ON

 Overlay of Ino metal and In Native Oxide – In (3d)
Native Oxide C (1s) = 285.4 eV
Flood gun OFF
  Overlay of Ino metal and In2O3 – In (3d)
Pure Oxide C (1s) = 285.0 eV
Chemical Shift: xx
 
→  Periodic Table  Copyright ©:  The XPS Library 

 

Overlay of In (3d5/2)
Ino Metal, In Native Oxide, & In2O3  

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Valence Band Spectra
Ino, In2O3 

Ino
Ion etched clean		 In2O3 – pressed pellet
Flood gun is ON,  Charge referenced so C (1s) = 285.0 eV

Overlay of Valence Band Spectra
for Ino metal and In2O3 

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Indium Minerals, Gemstones, and Chemical Compounds

 
Indium Iodide – InI3 Indite – FeIn2S4 Yanomamite – InAsO4-2H2O Indium Oxide – In2O3

→  Periodic Table 

 

 

Six (6) Chemical State Tables of In (3d5/2) 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 (3d5) 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
  • 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 (3d5/2) 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 signal (eg O (1s) or C (1s) having the most narrow FWHM and the lowest experimentally measured BE. 

→  Periodic Table 

Table #1

In (3d5/2) 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
In 49 In – element 443.8 eV   285.0 eV The XPS Library
In 49 InP (N*6) 443.9 eV 444.6 eV 284.8 eV Avg BE – NIST
In 49 CuInSe2 (N*2) 444.1 eV 444.7 eV 284.8 eV Avg BE – NIST
In 49 InSb (N*2) 444.1 eV 444.3 eV 284.8 eV Avg BE – NIST
In 49 In2O3 (N*11) 444.3 eV 445.0 eV 284.8 eV Avg BE – NIST
In 49 In-P 444.3 eV 444.8 eV 285.0 eV The XPS Library
In 49 InSb 444.3 eV 444.6 eV 285.0 eV The XPS Library
In 49 GaInAs 444.4 eV 444.9 eV 285.0 eV The XPS Library
In 49 In2Se3 (N*3) 444.5 eV 445.1 eV 284.8 eV Avg BE – NIST
In 49 In2Te3 (N*1) 444.5 eV   284.8 eV Avg BE – NIST
In 49 In-N 444.5 eV   285.0 eV The XPS Library
In 49 AuInOx (N*5) 444.6 eV 445.1 eV 284.8 eV Avg BE – NIST
In 49 In2Se3 444.6 eV 444.9 eV 285.0 eV The XPS Library
In 49 In2S3 (N*2) 444.7 eV 444.9 eV 284.8 eV Avg BE – NIST
In 49 In-(OH)3 (N*2) 445.0 eV 445.2 eV 284.8 eV Avg BE – NIST
In 49 InI3 (N*3) 445.0 eV 446.1 eV 284.8 eV Avg BE – NIST
In 49 InSnO 445.0 eV   285.0 eV The XPS Library
In 49 In-2O3 445.1 eV   285.0 eV The XPS Library
In 49 In-Ox ntv (N*1) 445.1 eV   284.8 eV Avg BE – NIST
In 49 InPO4 (N*2) 445.5 eV 445.7 eV 284.8 eV Avg BE – NIST
In 49 InBr3 (N*3) 445.7 eV 446.6 eV 284.8 eV Avg BE – NIST
In 49 In-Cl3 (N*3) 445.9 eV 446.9 eV 284.8 eV Avg BE – NIST
In 49 In-F3 (N*2) 446.2 eV 446.5 eV 284.8 eV Avg BE – NIST

 

Charge Referencing Notes

  • (N*number) identifies the number of NIST BEs that were averaged to produce the BE in the middle column.
  • The XPS Library uses Binding Energy Scale Calibration with 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 (1s) 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

In (3d5/2) Chemical State BEs from:  “PHI Handbook”

C (1s) BE = 284.8 eV

→  Periodic Table 

Copyright ©:  Ulvac-PHI

Table #3

In (3d5/2) Chemical State BEs from:  “Thermo-Scientific” Website

C (1s) BE = 284.8 eV

Chemical state Binding energy (eV), In (3d5/2)
In metal 443.8
In2O3 444.0

→  Periodic Table 

Copyright ©:  Thermo Scientific 

Table #4

In (3d5/2) 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

→  Periodic Table 

Copyright ©:  Mark Beisinger

Table #5

In (3d5/2) Chemical State BEs from:  “Techdb.podzone.net” Website

 

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

XPS(X線光電子分光法)スペクトル 化学状態 化学シフト ケミカルシフト

Element Level Compound B.E.(eV) min   max
In 3d5/2 In 443.8 ±0.3 443.5 ～ 444.0
In 3d5/2 InSb 444.1 ±0.3 443.8 ～ 444.3
In 3d5/2 In2Te3 444.6 ±0.3 444.3 ～ 444.8
In 3d5/2 InP 444.6 ±0.3 444.3 ～ 444.9
In 3d5/2 In2O3 444.6 ±0.3 444.3 ～ 444.9
In 3d5/2 InCl 444.9 ±0.3 444.6 ～ 445.2
In 3d5/2 In(OH)3 445.0 ±0.3 444.7 ～ 445.3
In 3d5/2 In(acac)3 445.5 ±0.3 445.2 ～ 445.7
In 3d5/2 Br2InEt4N 445.7 ±0.3 445.4 ～ 446.0
In 3d5/2 Br4InPr4N 446.0 ±0.3 445.7 ～ 446.3
In 3d5/2 InCl3 446.5 ±0.5 446.0 ～ 446.9

 

→  Periodic Table 

 


Histograms of NIST BEs for In (3d5/2) BEs

Important Note:  NIST Database defines Adventitious Hydrocarbon C (1s) BE = 284.8 eV for all insulators.

Histogram indicates:  443.8 eV for Ino based on 18 literature BEs Histogram indicates:  444.8 eV for In2O3 based on 12 literature BEs

Histogram indicates:  128.7 eV for P (2p3/2) in InP based on 14 literature BEs

Table #6


NIST Database of In (3d5/2) 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.

Important Note:  NIST Database defines Adventitious Hydrocarbon C (1s) BE = 284.8 eV for all insulators.

 

Element Spectral Line Formula Energy (eV) Reference
In 3d5/2 In 443.15  Click
In 3d5/2 In 443.15  Click
In 3d5/2 In 443.30  Click
In 3d5/2 In 443.30  Click
In 3d5/2 In 443.40  Click
In 3d5/2 In 443.40  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.60  Click
In 3d5/2 In 443.70  Click
In 3d5/2 In 443.70  Click
In 3d5/2 In 443.75  Click
In 3d5/2 In 443.75  Click
In 3d5/2 In 443.80  Click
In 3d5/2 In 443.80  Click
In 3d5/2 In 443.80  Click
In 3d5/2 In 443.80  Click
In 3d5/2 In 443.80  Click
In 3d5/2 In 443.80  Click
In 3d5/2 In 443.84  Click
In 3d5/2 In 443.84  Click
In 3d5/2 In 443.84  Click
In 3d5/2 In 443.84  Click
In 3d5/2 In 443.86  Click
In 3d5/2 In 443.86  Click
In 3d5/2 InI 443.90  Click
In 3d5/2 InP 443.90  Click
In 3d5/2 PbInTe 443.90  Click
In 3d5/2 In 444.00  Click
In 3d5/2 In 444.00  Click
In 3d5/2 In 444.00  Click
In 3d5/2 In 444.00  Click
In 3d5/2 In 444.00  Click
In 3d5/2 In 444.00  Click
In 3d5/2 In 444.00  Click
In 3d5/2 In 444.00  Click
In 3d5/2 InP 444.00  Click
In 3d5/2 H2/InP 444.00  Click
In 3d5/2 H2/(In,Ga)As 444.00  Click
In 3d5/2 AuIn2 444.03  Click
In 3d5/2 AuIn2 444.03  Click
In 3d5/2 AuIn 444.06  Click
In 3d5/2 AuIn 444.06  Click
In 3d5/2 CuInSe2 444.10  Click
In 3d5/2 InSb 444.10  Click
In 3d5/2 (In,Ga)AsOx 444.10  Click
In 3d5/2 Ar/(In,Ga)As 444.10  Click
In 3d5/2 N2O/(In,Ga)As 444.10  Click
In 3d5/2 InTe 444.10  Click
In 3d5/2 AuIn0.111 444.15  Click
In 3d5/2 AuIn0.111 444.15  Click
In 3d5/2 Au3In 444.18  Click
In 3d5/2 Au3In 444.18  Click
In 3d5/2 NH3/(In,Ga)As 444.20  Click
In 3d5/2 N2/(In,Ga)As 444.20  Click
In 3d5/2 (In2O3)0.90(SnO2)0.10 444.20  Click
In 3d5/2 Ga0.47In0.53As 444.22  Click
In 3d5/2 InAs 444.25  Click
In 3d5/2 In 444.30  Click
In 3d5/2 In 444.30  Click
In 3d5/2 InSb 444.30  Click
In 3d5/2 In2O3 444.30  Click
In 3d5/2 In2O3 444.30  Click
In 3d5/2 In2O3 444.30  Click
In 3d5/2 InPOx 444.30  Click
In 3d5/2 Ar/InP 444.30  Click
In 3d5/2 InAl6.5P0.4O13 444.30  Click
In 3d5/2 N2O/InP 444.30  Click
In 3d5/2 InAs 444.30  Click
In 3d5/2 In2O3 444.30  Click
In 3d5/2 As15In54Sb31 444.30  Click
In 3d5/2 InAs 444.31  Click
In 3d5/2 In2O3 444.40  Click
In 3d5/2 InP 444.40  Click
In 3d5/2 InMo6S8 444.40  Click
In 3d5/2 NH3/InP 444.40  Click
In 3d5/2 N2/InP 444.40  Click
In 3d5/2 InP0.5O2.8 444.40  Click
In 3d5/2 InP0.23O2.6 444.40  Click
In 3d5/2 Cu24.6In24.8Se50.6/SiO2 444.40  Click
In 3d5/2 In2Te3 444.40  Click
In 3d5/2 InSb 444.43  Click
In 3d5/2 In2Te3 444.50  Click
In 3d5/2 InP 444.50  Click
In 3d5/2 In2Se3 444.50  Click
In 3d5/2 (In2O3)0.95(SnO2)0.05 444.50  Click
In 3d5/2 In2O3 444.50  Click
In 3d5/2 In 444.60  Click
In 3d5/2 In 444.60  Click
In 3d5/2 In2O3 444.60  Click
In 3d5/2 InP 444.60  Click
In 3d5/2 InP 444.60  Click
In 3d5/2 AuInOx 444.60  Click
In 3d5/2 Cu24.3In25.8Se49.9/SiO2 444.60  Click
In 3d5/2 CuInS2 444.60  Click
In 3d5/2 InSbOx 444.60  Click
In 3d5/2 InSb 444.60  Click
In 3d5/2 InP 444.66  Click
In 3d5/2 CuInSe2 444.70  Click
In 3d5/2 In2O3 444.70  Click
In 3d5/2 In2O3 444.70  Click
In 3d5/2 In2S3 444.70  Click
In 3d5/2 InP 444.79  Click
In 3d5/2 In2Se3 444.80  Click
In 3d5/2 Cu29.1In22.4Se48.5/SiO2 444.80  Click
In 3d5/2 AuInOx 444.80  Click
In 3d5/2 AuInOx 444.80  Click
In 3d5/2 Cu25.6In24.4Se50/SiO2 444.80  Click
In 3d5/2 CuInSe2 444.80  Click
In 3d5/2 CuInSe2 444.80  Click
In 3d5/2 Cu24.6In24.8Se50.6Nx 444.80  Click
In 3d5/2 CuInS2 444.80  Click
In 3d5/2 CuInS2 444.80  Click
In 3d5/2 In40Se60 444.80  Click
In 3d5/2 InCl 444.90  Click
In 3d5/2 In2O3 444.90  Click
In 3d5/2 In2S3 444.90  Click
In 3d5/2 CdCr0.3In1.7S4 444.90  Click
In 3d5/2 CdCr0.3In1.7S4 444.90  Click
In 3d5/2 InAsO4 444.90  Click
In 3d5/2 CuInSSe 444.90  Click
In 3d5/2 In(OH)3 445.00  Click
In 3d5/2 InI3 445.00  Click
In 3d5/2 In2O3 445.00  Click
In 3d5/2 In2O3 445.00  Click
In 3d5/2 H2/(In,Ga)As 445.00  Click
In 3d5/2 AuInOx 445.00  Click
In 3d5/2 In2S3 445.06  Click
In 3d5/2 InOx 445.10  Click
In 3d5/2 InBr 445.10  Click
In 3d5/2 InCl 445.10  Click
In 3d5/2 In2O3 445.10  Click
In 3d5/2 In2Se3 445.10  Click
In 3d5/2 In(OH)3.nH20 445.10  Click
In 3d5/2 Co0.46Zn0.54In2.02S3.90 445.10  Click
In 3d5/2 N2/(In,Ga)As 445.10  Click
In 3d5/2 H2/InP 445.10  Click
In 3d5/2 AuInOx 445.10  Click
In 3d5/2 InPO4 445.10  Click
In 3d5/2 [N(C2H5)4][InCl2] 445.20  Click
In 3d5/2 In(OH)3 445.20  Click
In 3d5/2 NH3/(In,Ga)As 445.20  Click
In 3d5/2 [Mo3InS4(SO3C6H4CH3)2(H2O)10](SO3C6H4CH3)3.13H2O 445.20  Click
In 3d5/2 [N(CH3)4]2[InCl5] 445.30  Click
In 3d5/2 N2/InP 445.30  Click
In 3d5/2 N2O/(In,Ga)As 445.30  Click
In 3d5/2 In2O3 445.30  Click
In 3d5/2 [N(C3H7)4][InI4] 445.40  Click
In 3d5/2 [In(CH3C(O)CHC(O)CH3)3] 445.40  Click
In 3d5/2 NH3/InP 445.40  Click
In 3d5/2 Ar/(In,Ga)As 445.40  Click
In 3d5/2 CdIn2S2Se2 445.40  Click
In 3d5/2 InPO4.nH20 445.50  Click
In 3d5/2 Ar/InP 445.50  Click
In 3d5/2 N2O/InP 445.50  Click
In 3d5/2 Co0.07Zn0.93In2.10S4.02 445.50  Click
In 3d5/2 CuInS2 445.50  Click
In 3d5/2 (NH4)3[InF6] 445.60  Click
In 3d5/2 CoIn2S4 445.60  Click
In 3d5/2 CoIn2S4 445.60  Click
In 3d5/2 ZnIn2.02S3.95 445.60  Click
In 3d5/2 In2S3 445.60  Click
In 3d5/2 CoGaIn2S4 445.60  Click
In 3d5/2 [NH(CH3)3]3[InCl6] 445.70  Click
In 3d5/2 [N(C2H5)4][InBr2] 445.70  Click
In 3d5/2 [N(C2H5)4][InCl2]Cl2 445.70  Click
In 3d5/2 InBr3 445.70  Click
In 3d5/2 [N(CH3)4][InBr4] 445.70  Click
In 3d5/2 InPO4 445.70  Click
In 3d5/2 In(PO3)3 445.70  Click
In 3d5/2 [N(C3H7)4][InCl4] 445.80  Click
In 3d5/2 InI3 445.80  Click
In 3d5/2 InP 445.80  Click
In 3d5/2 Co0.35Zn0.65In2.06S3.72 445.80  Click
In 3d5/2 [N(C3H7)4][InBr4] 445.90  Click
In 3d5/2 InCl3 445.90  Click
In 3d5/2 [N(CH3)4]2[InBr5] 446.00  Click
In 3d5/2 InBr3 446.00  Click
In 3d5/2 InCl3 446.00  Click
In 3d5/2 In(PO3)4 446.00  Click
In 3d5/2 InI3 446.10  Click
In 3d5/2 InF3 446.20  Click
In 3d5/2 [NH3(CH3)]4[InCl7] 446.20  Click
In 3d5/2 InF3 446.50  Click
In 3d5/2 InCl3 446.50  Click
In 3d5/2 InBr3 446.60  Click
In 3d5/2 Cu23.4In26.5Se50.1/SiO2 446.60  Click
In 3d5/2 In2O3 446.70  Click
In 3d5/2 InCl3 446.90  Click
In 3d5/2 C32H16N8Zn:C32H16ClInN8(3:1) 450.50  Click
In 3d5/2 C32H16ClInN8 451.70  Click

 

 

Statistical Analysis of Binding Energies in NIST XPS Database of BEs

 

 

→  Periodic Table 

 

Advanced XPS Information Section

Expert Knowledge, Spectra, Features, Guidance and Cautions
for XPS Research Studies on Indium Materials

 

 

Expert Knowledge Explanations

→  Periodic Table 

 

 

Indium Chemical Compounds


Peak-fits and Overlays of Chemical State Spectra

Pure Indium, Ino:  In (3d)
Cu (2p3/2) BE = 932.6 eV		 In2O3:  In (3d5/2)
C (1s) BE = 285.0 eV		 InF3:  In (3d)
C (1s) BE = 285.0 eV

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Overlay of In (3d5/2) Spectra shown Above

C (1s) BE = 285.0 eV

 

Chemical Shift between In and In2O3:  0.4 eV
 Chemical Shift between In and InF3:   2.6 eV

 

→  Periodic Table 

 

Indium Oxide (In2O3)
pressed powder

Survey Spectrum from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV
 In (3d5/2) Chemical State Spectrum from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV
→  Periodic Table   
O (1s) Chemical State Spectrum from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV
 C (1s) Chemical State Spectrum from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV
→  Periodic Table 
  
Valence Band Spectrum from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV
 Auger Signals from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV
→  Periodic Table 
  
In (4s) Chemical State Spectrum from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV		 In (4p) Chemical State Spectrum from In2O3
Flood gun is ON, C (1s) BE = 285.0 eV

 

Multiplet Splitting Features for
Indium Compounds

In metal – NO Splitting for In (4s) In2O3  – NO Splitting Peaks for In (4s)

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

 

Indium Chemical Compounds

 

Indium Phosphide, InP
single crystal wafer

Survey In (3d)
→  Periodic Table   
C (1s) P (2p)
   

→  Periodic Table 

 

Quantitation Details and Information

Quantitation by XPS is often incorrectly done, in many laboratories, by integrating only the main peak, ignoring the Electron Loss peak, and the satellites that appear as much as 30 eV above the main peak.  By ignoring the electron loss peak and the satellites, the accuracy of the atom% quantitation is in error.

When using theoretically calculated Scofield cross-section values, the data must be corrected for the transmission function effect, use the calculated TPP-2M IMFP values, the pass energy effect on the transmission function, and the peak area used for calculation must include the electron loss peak area, shake-up peak area, multiplet-splitting peak area, and satellites that occur within 30 eV of the main peak.

 

Quantitation from Pure, Homogeneous Binary Compound
composed of Indium – In2O3

This section is focused on measuring and reporting the atom % quantitation that results by using:

  • Scofield cross-sections,
  • Spectra corrected to be free from Transmission Function effects
  • A Pass Energy that does not saturate the detector system in the low KE range (BE = 1000-1400 eV)
  • A focused beam of X-ray smaller than the field of view of the lens
  • An angle between the lens and the source that is ~55 deg that negates the effects of beta-asymmetry
  • TPP-2M inelastic mean free path values, and
  • Either a linear background or an iterated Shirley (Sherwood-Proctor) background to define peak areas

The results show here are examples of a method being developed that is expected to improve the “accuracy” or “reliability” of the atom % values produced by XPS.

→  Periodic Table 

 

 

XPS Study of UHV Gas Captured by Freshly Ion Etched Indium
 
Reveals Chemical Shifts and Chemical States that Develop from Highly Reactive Pure Ino

Surface was strongly Ar+ ion etched to remove all contaminants, and
then allowed to react overnight with the UHV Gases – CO, H2, H2O, O2 & CH4
that normally reside inside on the walls of the chamber, on the sample stage,
and on the nearby un-etched surface a total of 10-14 hours.  UHV pump was a Cryopump.
Initial spectra are at the front.  Final spectra are at the rear. Flood gun is OFF.
 
 
 
In (3d) Signal
  O (1s) Signal C (1s) Signal
     
 
 

Copyright ©:  The XPS Library

 

Auger Survey Spectrum from InN
using Charge Control

 

In (MNN) Signal

Features Observed

  • xx
  • xx
  • xx

→  Periodic Table 

 

Indium Alloys

   
XxCu XxCu
→  Periodic Table   
XxCu XxCu

 

Copyright ©:  The XPS Library 

 

 

XPS Facts, Guidance & Information

→  Periodic Table 

    Element   Indium (In)
  
    Primary XPS peak used for Peak-fitting:   In (3d5/2)  
    Spin-Orbit (S-O) splitting for Primary Peak:   Spin-Orbit splitting for “d” orbital, ΔBE = 7.5 eV
  
    Binding Energy (BE) of Primary XPS Signal:   443 eV
  
    Scofield Cross-Section (σ) Value:   In (3d5/2) = 13.32    In (3d3/2) = 9.22
  
    Conductivity:   In resistivity =  
Native Oxide suffers Differential Charing		  
    Range of In (3d5/2) Chemical State BEs:   435 – 460 eV range   (Ino to InF3)  
    Signals from other elements that overlap
In (3d5/2) Primary Peak:		   xx (xx)  
    Bulk Plasmons:   ~xx eV above peak max for pure  
    Shake-up Peaks:   xx  
    Multiplet Splitting Peaks:   xx  

 

 

 General Information about
XXX Compounds:		   xx  
    Cautions – Chemical Poison Warning  

xx 

  

Copyright ©:  The XPS Library 

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Information Useful for Peak-fitting In (3d5/2)

  • FWHM (eV) of In (3d5/2) for Pure Ino :  ~0.7 eV using 25 eV Pass Energy after ion etching:
  • FWHM (eV) of In (3d5/2) for In2O3:  ~1.3 eV using 50 eV Pass Energy  (before ion etching)
  • Binding Energy (BE) of Primary Signal used for Measuring Chemical State Spectra:  444 eV for In (3d5/2) with +/- 0.2 uncertainty
  • List of XPS Peaks that can Overlap Peak-fit results for In (3d5/2):  xxxx

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General Guidelines for Peak-fitting XPS Signals

  • Typical Energy Resolution for Pass Energy (PE) setting used to measure Chemical State Spectra on Various XPS Instruments
    • Ag (3d5/2) FWHM (eV) = ~0.95 eV for PE 50 on Thermo K-Alpha
    • Ag (3d5/2) FWHM (eV) = ~1.00 eV for PE 80 on Kratos Nova
    • Ag (3d5/2) FWHM (eV) = ~0.95 eV for PE 45 on PHI VersaProbe
  • FWHM (eV) of Pure Elements: Ranges from 0.4 to 1.0 eV across the periodic table
  • FWHM of Chemical State Peaks in any Chemical Compound:  Ranges from 1.1 to 1.6 eV  (in rare cases FWHM can be 1.8 to 2.0 eV)
  • FWHM of Pure Element versus FWHM of Oxide:  Pure element FWHM << Oxide FWHM  (e.g. 0.8 vs 1.5 eV, roughly 2x)
  • If FWHM Greater than 1.6 eV:  When a peak FWHM is larger than 1.6 eV, it is best to add another peak to the peak-fit envelop.
  • BE (eV) Difference in Chemical States: The difference in chemical state BEs is typically 1.0-1.3 eV apart.  In rare cases, <0.8 eV.
  • Number of Peaks to Use:  Use minimum. Do not use peaks with FWHM < 1.0 eV unless it is a or a conductive compound.
  • Typical Peak-Shape:  80% G: 20% L,   or Voigt : 1.4 eV Gaussian and 0.5 eV Lorentzian
  • Spin-Orbit Splitting of Two Peaks (due to Coupling):  The ratio of the two (2) peak areas must be constrained.

Notes:

  • Other Oxidation States can appear as small peaks when peak-fitting
  • Pure element signals normally have asymmetric tails that should be included in the peak-fit.
  • Gaseous state materials often display asymmetric tails due to vibrational broadening.
  • Peak-fits of C (1s) in polymers include an asymmetric tail when the energy resolution is very high.
  • Binding energy shifts of some compounds are negative due to unusual electron polarization.

→  Periodic Table 

 

Contaminants Specific to Indium

  • Indium develops a thick native oxide due to the reactive nature of clean Indium.
  • The native oxide and hydroxide of In is 4-6 nm thick.
  • Indium thin films often have a low level of iron (Fe) in the bulk as a contaminant or to strengthen the thin film
  • Indium forms a low level of carbide when the surface is ion etched inside the analysis chamber

 

Commonplace Contaminants

  • Carbon and Oxygen are common contaminants that appear on nearly all surfaces. The amount of Carbon usually depends on handling.
  • Carbon is usually the major contaminant.  The amount of carbon ranges from 5-50 atom%.
  • Carbon contamination is attributed to air-borne organic gases that become trapped by the surface, oils transferred to the surface from packaging containers, static electricity, or handling of the product in the production environment.
  • Carbon contamination is normally a mixture of different chemical states of carbon (hydrocarbon, alcohol or ether, and ester or acid).
  • Hydrocarbon is the dominant form of carbon contamination. It is normally 2-4x larger than the other chemical states of carbon.
  • Carbonate peaks, if they appear, normally appear ~4.5 eV above the hydrocarbon C (1s) peak max BE.
  • Low levels of carbonate is common on many s that readily oxidize in the air.
  • High levels of carbonate appear on reactive oxides and various hydroxides.  This is due to reaction between the oxide and CO2 in the air.
  • Hydroxide contamination peak is due to the reaction with residual water in the lab air or the vacuum.
  • The O (1s) BE of the hydroxide (water) contamination normally appears 0.5 to 1.0 eV above the oxide peak
  • Sodium (Na), Potassium (K), Sulfur (S) and Chlorine (Cl) are common trace to low level contaminants
  • To find low level contaminants it is very useful to vertically expand the 0-600 eV region of the survey spectrum by 5-10X
  • A tiny peak that has 3 or more adjacent data-points above the average noise of the background is considerate to be a real peak
  • Carbides can appear after ion etching various reactive s.  Carbides form due to the residual CO and CH4 in the vacuum.
  • Ion etching can produce low oxidation states of the material being analyzed.  These are newly formed contaminants.
  • Ion etching polymers by using standard Ar+ ion guns will destroy the polymer, converting it into a graphitic type of carbon

→  Periodic Table 

 

Data Collection Guidance

  • Chemical state differentiation can be difficult
  • Collect principal In (3d5/2) peak
  • Long time exposures (high dose) to X-rays can degrade various polymers, catalysts, high oxidation state compounds
  • During XPS analysis, water or solvents can be lost due to high vacuum or irradiation with X-rays or Electron flood gun
  • Auger signals can sometimes be used to discern chemical state shifts when XPS shifts are very small

→  Periodic Table 

 

Data Collection Settings for Indium (In)

  • Conductivity:  Indium readily develops a native oxide that is sensitive to Flood Gun – Differential Charging Possible – float sample recommended
  • Primary Peak (XPS Signal) used to measure Chemical State Spectra:  In (3d5/2) at 444 eV
  • Recommended Pass Energy for Measuring Chemical State Spectrum:  40-50 eV    (Produces Ag (3d5/2) FWHM ~0.7 eV)
  • Recommended # of Scans for Measuring Chemical State Spectrum:  4-5 scans normally   (Use 10-25 scans to improve S/N)
  • Dwell Time:  50 msec/point
  • Step Size:  0.1 eV/point   (0.1 eV/step or 0.1 eV/channel)
  • Standard BE Range for Measuring Chemical State Spectrum:  430 – 460 eV
  • Recommended Extended BE Range for Measuring Chemical State Spectrum:  430 – 530eV
  • Recommended BE Range for Survey Spectrum:  -10 to 1,100 eV   (above 1,100 eV there are no useful XPS signals, except for Ge and Ga)
  • Typical Time for Survey Spectrum:  3-5 minutes for newer instruments, 5-10 minutes for older instruments
  • Typical Time for a single Chemical State Spectrum with high S/N:  5-10 minutes for newer instruments, 10-15 minutes for older instruments 

→  Periodic Table 

 

Effects of Argon Ion Etching

  • Carbides appear after ion etching In and various reactive surfaces.  Carbides form due to the presence of residual CO and CH4 in the vacuum.
  • Ion etching can produce low oxidation states of the material being analyzed.  These are newly formed contaminants.
  • Ion etching polymers by using standard Ar+ ion guns will destroy the polymer, converting it into a graphitic type of carbon

 

→  Periodic Table 

Copyright ©:  The XPS Library 
 
 
Gas Phase XPS or UPS Spectra
 
 
     
     
     
     
     
     
     
     
     
 
 
 

 

Chemical State Spectra from Literature
 
 
xxx
 

End of File