Specific Process Knowledge/Characterization/AFM: Atomic Force Microscopy/KPFM - Revision history

Bghe: /* Here I shortly explain how to calibrate to get work function values */

2025-09-04T13:37:35Z

Here I shortly explain how to calibrate to get work function values

Bghe at 14:18, 28 April 2023

2023-04-28T14:18:15Z

← Older revision		Revision as of 16:18, 28 April 2023
Line 9:		Line 9:
	===Here I shortly explain how to calibrate to get work function values===		===Here I shortly explain how to calibrate to get work function values===

	To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: ~~AN10-RevA1-PeakForce_KPFM-appNote.pdf~~		To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: [[File:PeakForce-Kelvin-Probe-Force-Microscopy-App-Note-BRUKER.pdf]] - used with permission
	[[File:PeakForce-Kelvin-Probe-Force-Microscopy-App-Note-BRUKER.pdf]] - used with permission

	[[File:KPFM workfunction Au Si Al.jpg\|400px]]		[[File:KPFM workfunction Au Si Al.jpg\|400px]]

Bghe at 14:17, 28 April 2023

2023-04-28T14:17:42Z

← Older revision		Revision as of 16:17, 28 April 2023
Line 10:		Line 10:

	To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: AN10-RevA1-PeakForce_KPFM-appNote.pdf		To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: AN10-RevA1-PeakForce_KPFM-appNote.pdf
	[[File:~~AN10~~-~~RevA1~~-~~PeakForce_KPFM~~-~~appNote~~.~~PDF~~]]		[[File:PeakForce-Kelvin-Probe-Force-Microscopy-App-Note-BRUKER.pdf]] - used with permission

	[[File:KPFM workfunction Au Si Al.jpg\|400px]]		[[File:KPFM workfunction Au Si Al.jpg\|400px]]

Bghe at 14:13, 28 April 2023

2023-04-28T14:13:46Z

← Older revision		Revision as of 16:13, 28 April 2023
Line 10:		Line 10:

	To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: AN10-RevA1-PeakForce_KPFM-appNote.pdf		To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: AN10-RevA1-PeakForce_KPFM-appNote.pdf
	[[File:AN10-RevA1-PeakForce_KPFM-appNote.~~pdf~~]]		[[File:AN10-RevA1-PeakForce_KPFM-appNote.PDF]]

	[[File:KPFM workfunction Au Si Al.jpg\|400px]]		[[File:KPFM workfunction Au Si Al.jpg\|400px]]

Bghe at 14:13, 28 April 2023

2023-04-28T14:13:28Z

← Older revision		Revision as of 16:13, 28 April 2023
Line 10:		Line 10:

	To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: AN10-RevA1-PeakForce_KPFM-appNote.pdf		To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: AN10-RevA1-PeakForce_KPFM-appNote.pdf
			[[File:AN10-RevA1-PeakForce_KPFM-appNote.pdf]]

	[[File:KPFM workfunction Au Si Al.jpg\|400px]]		[[File:KPFM workfunction Au Si Al.jpg\|400px]]

Bghe: /* Here I shortly explain how to calibrate to get work function values */

2022-09-06T11:35:22Z

Here I shortly explain how to calibrate to get work function values

← Older revision		Revision as of 13:35, 6 September 2022
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	For reference I prefer using the gold as the two other materials form oxides and I think that using the values for Si and Al are then less accurate.		For reference I prefer using the gold as the two other materials form oxides and I think that using the values for Si and Al are then less accurate.
	But even for gold you can find several different values for the work function. Take a look at ~~these references~~: ~~[http://student.ndhu.edu.tw/~d9914102/Teaching/EM/Paper/data/The%20work%20function%20of%20the%20elements%20and%20its%20periodicity.pdf],~~ [https://en.wikipedia.org/wiki/Work_function#Work_functions_of_elements[11]]. The work function value range for gold seems to be from 5.10eV to 5.47eV. 5.10eV for poly crystaline gold and the higher values for single crystalline gold. I believe I do not have single crystalline gold, so I will use the 5.10eV as the reference value for the sample.		But even for gold you can find several different values for the work function. Take a look at this reference: [https://en.wikipedia.org/wiki/Work_function#Work_functions_of_elements[11]]. The work function value range for gold seems to be from 5.10eV to 5.47eV. 5.10eV for poly crystaline gold and the higher values for single crystalline gold. I believe I do not have single crystalline gold, so I will use the 5.10eV as the reference value for the sample.

	To get the work function of the your sample of interest, you need to find the work function of the tip as what you measure with KPFM is the work function difference between the tip and the sample.		To get the work function of the your sample of interest, you need to find the work function of the tip as what you measure with KPFM is the work function difference between the tip and the sample.

Jmli at 20:08, 25 November 2019

2019-11-25T20:08:11Z

← Older revision		Revision as of 22:08, 25 November 2019
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	'''Feedback to this page''': '''[mailto:labadviser@~~danchip~~.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.~~danchip~~.dtu.dk/index.php/Specific_Process_Knowledge/Characterization/AFM:_Atomic_Force_Microscopy/KPFM click here]'''		'''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Characterization/AFM:_Atomic_Force_Microscopy/KPFM click here]'''

	''By Berit Herstrøm @~~danchip~~ January 2018''		''By Berit Herstrøm @nanolab January 2018''

	KPFM (Kelvin Probe Force Microscopy) measurements can be done with this AFM Icon. It is best for mapping the surface potential on a sample with nanometer resolution but it can also be calibrated to give quantitative values.		KPFM (Kelvin Probe Force Microscopy) measurements can be done with this AFM Icon. It is best for mapping the surface potential on a sample with nanometer resolution but it can also be calibrated to give quantitative values.
Line 18:		Line 18:
	To get the work function of the your sample of interest, you need to find the work function of the tip as what you measure with KPFM is the work function difference between the tip and the sample.		To get the work function of the your sample of interest, you need to find the work function of the tip as what you measure with KPFM is the work function difference between the tip and the sample.

	Measured surface potential = Work ~~funtion~~ (Tip) - Work function (sample)		Measured surface potential = Work function (Tip) - Work function (sample)

	So		So
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	Work function (Tip) = Measured surface potential*e + Work function (sample)		Work function (Tip) = Measured surface potential*e + Work function (sample)

	When ~~measurening~~ on the gold to find the work function of the tip:		When measuring on the gold to find the work function of the tip:

	Work function (Tip) = Measured surface potential*e + 5.10eV		Work function (Tip) = Measured surface potential*e + 5.10eV

Bghe at 14:36, 28 March 2019

2019-03-28T14:36:43Z

← Older revision		Revision as of 16:36, 28 March 2019
Line 5:		Line 5:
	KPFM (Kelvin Probe Force Microscopy) measurements can be done with this AFM Icon. It is best for mapping the surface potential on a sample with nanometer resolution but it can also be calibrated to give quantitative values.		KPFM (Kelvin Probe Force Microscopy) measurements can be done with this AFM Icon. It is best for mapping the surface potential on a sample with nanometer resolution but it can also be calibrated to give quantitative values.

			To get the potential/work function: set the Interleave mode to "Lift" while scanning with the KPFM workspace

	===Here I shortly explain how to calibrate to get work function values===		===Here I shortly explain how to calibrate to get work function values===

Bghe: /* Here I shortly explain how to calibrate to get work function values */

2019-03-28T12:21:13Z

Here I shortly explain how to calibrate to get work function values

← Older revision		Revision as of 14:21, 28 March 2019
Line 22:		Line 22:
	Work function (Tip) = Measured surface potential*e + Work function (sample)		Work function (Tip) = Measured surface potential*e + Work function (sample)

	When measurening on the gold to ~~fin~~ the work function of the tip:		When measurening on the gold to find the work function of the tip:

	Work function (Tip) = Measured surface potential*e + 5.10eV		Work function (Tip) = Measured surface potential*e + 5.10eV

Bghe at 09:35, 9 January 2018

2018-01-09T09:35:21Z

← Older revision		Revision as of 11:35, 9 January 2018
Line 1:		Line 1:
	'''Feedback to this page''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Characterization/AFM:_Atomic_Force_Microscopy/KPFM click here]'''		'''Feedback to this page''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Characterization/AFM:_Atomic_Force_Microscopy/KPFM click here]'''

			''By Berit Herstrøm @danchip January 2018''

	KPFM (Kelvin Probe Force Microscopy) measurements can be done with this AFM Icon. It is best for mapping the surface potential on a sample with nanometer resolution but it can also be calibrated to give quantitative values.		KPFM (Kelvin Probe Force Microscopy) measurements can be done with this AFM Icon. It is best for mapping the surface potential on a sample with nanometer resolution but it can also be calibrated to give quantitative values.

← Older revision		Revision as of 15:37, 4 September 2025
Line 7:		Line 7:
	To get the potential/work function: set the Interleave mode to "Lift" while scanning with the KPFM workspace		To get the potential/work function: set the Interleave mode to "Lift" while scanning with the KPFM workspace

	===Here I shortly ~~explain~~ how to calibrate to get work function values===		===Here is shortly explained how to calibrate to get the work function values===

	To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: [[File:PeakForce-Kelvin-Probe-Force-Microscopy-App-Note-BRUKER.pdf]] - used with permission		To get a quantitative value for the work function of a sample material you need to calibrate the AFM tip you are using. This is done by measuring a material with a known work function. We do not have a certified sample for this but we are using a sample that came with the system. It has some lines of Au-Si-Al right next to each other. The below image is from the Bruker application note: [[File:PeakForce-Kelvin-Probe-Force-Microscopy-App-Note-BRUKER.pdf]] - used with permission
Line 14:		Line 14:

	For reference I prefer using the gold as the two other materials form oxides and I think that using the values for Si and Al are then less accurate.		For reference I prefer using the gold as the two other materials form oxides and I think that using the values for Si and Al are then less accurate.
	But even for gold you can find several different values for the work function. Take a look at this reference: [https://en.wikipedia.org/wiki/Work_function#Work_functions_of_elements[11]]. The work function value range for gold seems to be from 5.10eV to 5.47eV. 5.10eV for poly ~~crystaline~~ gold and the higher values for single crystalline gold. I believe I do not have single crystalline gold, so I will use the 5.10eV as the reference value for the sample.		But even for gold you can find several different values for the work function. Take a look at this reference: [https://en.wikipedia.org/wiki/Work_function#Work_functions_of_elements[11]]. The work function value range for gold seems to be from 5.10eV to 5.47eV. 5.10eV for poly crystalline gold and the higher values for single crystalline gold. I believe I do not have single crystalline gold, so I will use the 5.10eV as the reference value for the sample.

	To get the work function of the ~~your~~ sample of interest, you need to find the work function of the tip as what you measure with KPFM is the work function difference between the tip and the sample.		To get the work function of the sample of interest, you need to find the work function of the tip because what you measure with KPFM is the work function difference between the tip and the sample.

	Measured surface potential = Work function (Tip) - Work function (sample)		Measured surface potential = Work function (Tip) - Work function (sample)
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	Work function (Tip) = -0.514 V * e + 5.10 eV = 4.586 eV		Work function (Tip) = -0.514 V * e + 5.10 eV = 4.586 eV

	The value can be typed into the workspace and after that the potential window will show you the work function.		The value can be typed into the workspace and after that the potential window will show you the work function of your material.

	'''The accuracy of your results are limited by'''		'''The accuracy of your results are limited by'''
	*the accuracy of the value you use for calibration.		*the accuracy of the value you use for calibration.
	*It is also limited by the state of the tip. If the tip radius change after the calibration this will affect your results and the tip should be calibrated again.		*It is also limited by the state of the tip. If the tip radius change after the calibration this will affect your results and the tip should be calibrated again.
	*Other things to consider is that the sample surface must be grounded to the stage. Here you can use Al-tape from the surface of the your sample (be very careful not to hit the tape with the AFM probe.		*Other things to consider is that the sample surface must be grounded to the stage. Here you can use Al-tape from the surface of the your sample (be very careful not to hit the tape with the AFM probe).