Preventing probe induced topography correlated artifacts in Kelvin Probe Force Microscopy

Polak, Leo; Wijngaarden, Rinke J.

doi:10.1016/j.ultramic.2016.09.014

Cited by 9 publications

(8 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, Kelvin probe force microscopy (KPFM) and electric force microscopy (EFM) measured the built-in potential in single PbS–CdS and CdS–Cu 2 S nanorods, respectively. , However, the characterization of nanoscale interfaces by probe methods is sensitive to the surface of the semiconductor, which often has different properties from the interior of the structure . Moreover, probe methods are limited to planar structures due to geometrical limitations . Such studies are occasionally accompanied by TEM analysis which can determine the composition and crystal structure, even at atomic scale lateral resolution …”

mentioning

confidence: 99%

“…14 Moreover, probe methods are limited to planar structures due to geometrical limitations. 15 Such studies are occasionally accompanied by TEM analysis which can determine the composition and crystal structure, even at atomic scale lateral resolution. 13 An additional capability of TEM is OAEH, which can map variations in electrostatic potential at high lateral resolution, around 1 nm, and with a stated potential sensitivity of 30 mV.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Mapping Charge Distribution in Single PbS Core – CdS Arm Nano-Multipod Heterostructures by Off-Axis Electron Holography

Chalasani¹,

Pekin²,

Rabkin³

et al. 2017

Nano Lett.

View full text Add to dashboard Cite

We synthesized PbS core-CdS arm nanomultipod heterostructures (NMHs) that exhibit PbS{111}/CdS{0002} epitaxial relations. The PbS-CdS interface is chemically sharp as determined by aberration corrected transmission electron microscopy (TEM) and compared to density functional theory (DFT) calculations. Ensemble fluorescence measurements show quenching of the optical signal from the CdS arms indicating charge separation due to the heterojunction with PbS. A finite-element three-dimensional (3D) calculation of the Poisson equation shows a type-I heterojunction, which would prevent recombination in the CdS arm after optical excitation. To examine charge redistribution, we used off-axis electron holography (OAEH) in the TEM to map the electrostatic potential across an individual heterojunction. Indeed, a built-in potential of 500 mV is estimated across the junction, though as opposed to the thermal equilibrium calculations significant accumulation of positive charge at the CdS side of the interface is detected. We conclude that the NMH multipod geometry prevents efficient removal of generated charge carriers by the high energy electrons of the TEM. Simulations of generated electron-hole pairs in the insulated CdS arm of the NMH indeed show charge accumulation in agreement with the experimental measurements. Thus, we show that OAEH can be used as a complementary methodology to ensemble measurements by mapping the charge distribution in single NMHs with complex geometries.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

Mapping Charge Distribution in Single PbS Core – CdS Arm Nano-Multipod Heterostructures by Off-Axis Electron Holography

Chalasani¹,

Pekin²,

Rabkin³

et al. 2017

Nano Lett.

View full text Add to dashboard Cite

show abstract

“…4d) insets). Here, the use of uniformly PtIr-coated tips, enables avoidance of the topography correlated artifacts, unlike some previous studies [36]. Taking into account the opening angle of about 40 degrees and the nanowires' average height of 18(8) nm, the tip diameter at the level of nanowires top surface would be about 40 nm, meaning that the CPD resolution is approaching the topography resolution which is the ultimate physical limit of FM-KPFM technique [11].…”

Section: Resultsmentioning

confidence: 97%

KPFM work function characterization of ongoing reduction and oxidation of transition metal oxide crystals on examples of SrTiO₃ and TiO nanowires

Wrana¹,

Cieślik²,

Bełza³

et al. 2019

Preprint

View full text Add to dashboard Cite

Controlling the work function of transition metal oxides is of key importance towards future energy production and storage. As majority of applications comprise the use of heterostructures, the most suitable experimental technique is Kelvin Probe Force Microscopy, providing excellent energetic and lateral resolution. In this paper we demonstrate the possibility of the precise work function characterization using the example of artificially formed crystalline titanium monoxide TiO nanowires on strontium titanate SrTiO3 surfaces providing a sharp atomic interface. The measured value of 3.31(21) eV is the first experimental work function evidence for a cubic TiO phase, being additionally subjected to significant variations among different crystallographic facets. Despite the remarkable height of the formed TiO nanowires, FM-KPFM proved to be able to achieve high lateral resolution of 15 nm, which is close to the topographical limits. In this study we show also the unique possibility of obtaining conductivity and work function maps on the same area, by combining contact and non-contact atomic force microscopy. As most of real applications require ambient operating conditions, we have additionally checked the impact of air venting on the work function of the TiO/SrTiO3(100) heterostructure, proving the surface re-oxidation occurs and results in work function increases of 0.9 eV and 0.6 eV for SrTiO3 and TiO, respectively. In addition, the influence of physisorbed species was estimated to contribute 0.4 eV and 0.2 eV to the work function of both structures. The presented method of the KPFM (and LC-AFM) employment for the work function characterization of transition metal oxides may help to understand the reduction and oxidation impact on electronic properties, which is of high importance towards the development of effective sensing and catalytic devices.

show abstract

“…We have studied the work function and surface potential distribution of the perovskite films by the KPFM technique in the dark (Figure 5). KPFM is a powerful tool for measuring the 31 The increase in perovskite grain size by probe sonication also helps in increasing the absorption coefficient and path length of light propagation. 4,32 With a larger grain size in the compact films, the absorbance of the sonicated perovskites is higher and red-shifted than the pristine M0 and CF0 (Figure 6a,d).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Positive Feedback Mechanism of Probe Sonication for the Perovskite Films in Solar Cells

Chaudhary,

Bhattacharyya

2023

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

The performance of perovskite solar cells (PSCs) is governed by the quality of perovskite films, whereby compact, pinhole-free perovskite films are desired, in addition to its composition. We have demonstrated probe sonication as a processing technique to provide positive feedback for enhancing the perovskite film quality and photovoltaic parameters, with two systems, CH3NH3PbI3 (MAPbI3) and Cs0.17FA0.83Pb(I0.83Br0.17)3. In probe sonication, the ultrasound results in the formation, growth, and collapse of the bubbles through shock wave inside the gas phase of the collapsing bubble. This phenomenon has a chemical impact on the nucleation of the perovskite phases and interconnectivity of the grains. The 60 min sonicated films with stronger hydrogen bonding network are devoid of unwanted Pb0, δ-FAPbI3, and PbI2 phases, having tightly packed homogeneous grains, minimum electron–hole recombination pathways, and improved light absorption. The surface potential remains mostly unaltered across the grains and grain boundaries, and the realignment of the Fermi energy (E F) favors facile carrier transport. The photoconversion efficiency (PCE) of the MAPbI3 and Cs0.17FA0.83Pb(I0.83Br0.17)3 devices is improved by 28.1 and 17.2% in comparison to the pristine perovskites, respectively. The 60 min sonicated Cs0.17FA0.83Pb(I0.83Br0.17)3 PSC has 20.20 ± 0.40% PCE with 1000 h ambient stability having >60% retention of the original PCE.

show abstract

Preventing probe induced topography correlated artifacts in Kelvin Probe Force Microscopy

Cited by 9 publications

References 22 publications

Mapping Charge Distribution in Single PbS Core – CdS Arm Nano-Multipod Heterostructures by Off-Axis Electron Holography

Mapping Charge Distribution in Single PbS Core – CdS Arm Nano-Multipod Heterostructures by Off-Axis Electron Holography

KPFM work function characterization of ongoing reduction and oxidation of transition metal oxide crystals on examples of SrTiO₃ and TiO nanowires

Positive Feedback Mechanism of Probe Sonication for the Perovskite Films in Solar Cells

Contact Info

Product

Resources

About

Preventing probe induced topography correlated artifacts in Kelvin Probe Force Microscopy

Cited by 9 publications

References 22 publications

Mapping Charge Distribution in Single PbS Core – CdS Arm Nano-Multipod Heterostructures by Off-Axis Electron Holography

Mapping Charge Distribution in Single PbS Core – CdS Arm Nano-Multipod Heterostructures by Off-Axis Electron Holography

KPFM work function characterization of ongoing reduction and oxidation of transition metal oxide crystals on examples of SrTiO3 and TiO nanowires

Positive Feedback Mechanism of Probe Sonication for the Perovskite Films in Solar Cells

Contact Info

Product

Resources

About

KPFM work function characterization of ongoing reduction and oxidation of transition metal oxide crystals on examples of SrTiO₃ and TiO nanowires