Dual-heterodyne Kelvin probe force microscopy

• Benjamin Grévin,
• Fatima Husainy,
• Dmitry Aldakov and
• Cyril Aumaître

Beilstein J. Nanotechnol. 2023, 14, 1068–1084, doi:10.3762/bjnano.14.88

• mode (DHe-KPFM spectroscopy), and 2D dynamic images can be acquired in data cube mode. The capabilities of DHe-KPFM in terms of time-resolved measurements, surface photovoltage (SPV) imaging, and detection of weak SPV signals are demonstrated through a series of experiments on difference surfaces: a

• ; intermodulation; KPFM; nc-AFM; surface photovoltage; time-resolved measurements; Introduction Kelvin probe force microscopy (KPFM) is a well-known variant of AFM that allows probing at the nanoscale the electrostatic landscape on the surface of a sample by measuring the so-called contact potential difference

• development of KPFM-based approaches specifically designed to investigate photogeneration mechanisms and charge dynamics at the nanoscale in photovoltaic and optoelectronic materials is an active research area. In photoassisted KPFM, the idea is to probe the surface photovoltage (SPV), which is the

Spatial mapping of photovoltage and light-induced displacement of on-chip coupled piezo/photodiodes by Kelvin probe force microscopy under modulated illumination

• Zeinab Eftekhari,
• Nasim Rezaei,
• Hidde Stokkel,
• Jian-Yao Zheng,
• Andrea Cerreta,
• Ilka Hermes,
• Minh Nguyen,
• Guus Rijnders and
• Rebecca Saive

Beilstein J. Nanotechnol. 2023, 14, 1059–1067, doi:10.3762/bjnano.14.87

• In this work, a silicon photodiode integrated with a piezoelectric membrane is studied by Kelvin probe force microscopy (KPFM) under modulated illumination. Time-dependent KPFM enables simultaneous quantification of the surface photovoltage generated by the photodiode as well as the resulting

• spatially map voltage-induced oscillation of various sizes of piezoelectric membranes without the photodiode to investigate their position- and size-dependent displacement. Keywords: Kelvin probe force microscopy (KPFM); light-driven micro/nano systems; piezoelectric membrane; surface photovoltage (SPV

• in combination with illumination has been used to investigate photo-generated charge carriers of photovoltaic materials and devices. This is done by determining the CPD shift under illumination known as surface photovoltage (SPV) by calculating SPV = CPDlight − CPDdark, whereas CPDdark is the CPD in

Cross-sectional Kelvin probe force microscopy on III–V epitaxial multilayer stacks: challenges and perspectives

• Mattia da Lisca,
• José Alvarez,
• James P. Connolly,
• Nicolas Vaissiere,
• Karim Mekhazni,
• Jean Decobert and
• Jean-Paul Kleider

Beilstein J. Nanotechnol. 2023, 14, 725–737, doi:10.3762/bjnano.14.59

• ; surface photovoltage; Introduction The development of photovoltaic (PV) technologies has progressed significantly over the past twenty years as a result of considerable advancements in solar cell device engineering and material science. As a consequence, solar cells have turned into complex structures

• 5.75 eV. KPFM measurements were performed under dark conditions and under illumination on the cross section of the sample. The acquisition of VCPD/light enables the evaluation of the surface photovoltage (SPV), which is defined as the light-induced change of the contact potential difference at the

• surface of a photoactive material [20]. Since the surface potential of the tip is assumed to be unaffected by illumination, the difference between VCPD/light and VCPD/dark is equal to the change in surface potential of the sample between illumination and dark, which defines the surface photovoltage: It is

Direct measurement of surface photovoltage by AC bias Kelvin probe force microscopy

• Masato Miyazaki,
• Yasuhiro Sugawara and
• Yan Jun Li

Beilstein J. Nanotechnol. 2022, 13, 712–720, doi:10.3762/bjnano.13.63

• Masato Miyazaki Yasuhiro Sugawara Yan Jun Li Department of Applied Physics, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan 10.3762/bjnano.13.63 Abstract Surface photovoltage (SPV) measurements are a crucial way of investigating optoelectronic and

• modulated external disturbances. Keywords: atomic force microscopy; Kelvin probe force microscopy; photocatalyst; surface photovoltage; titanium dioxide; Introduction Surface photovoltage (SPV) is the change in surface potential caused by light illumination [1][2] and is measured to determine such

Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review

• Viet Van Pham,
• Hong-Huy Tran,
• Thao Kim Truong and
• Thi Minh Cao

Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7

• generation architectural structure of heterojunctions toward visible-light-driven NO degradation”, article no. 117510, Copyright (2021), with permission from Elsevier. This content is not subject to CC BY 4.0. (a) Surface photovoltage spectroscopy, (b) transient photocurrent responses, (c) EIS Nyquist plots

Implementation of data-cube pump–probe KPFM on organic solar cells

• Benjamin Grévin,
• Olivier Bardagot and
• Renaud Demadrille

Beilstein J. Nanotechnol. 2020, 11, 323–337, doi:10.3762/bjnano.11.24

• PTB7 and PC71BM is subsequently investigated by recording point-spectroscopy curves as a function of the optical power at the cathode and by mapping 2D time-resolved images of the surface photovoltage of the bare organic active layer. Keywords: bulk heterojunctions; Kelvin probe force microscopy (KPFM

• . Errors in the surface photovoltage (SPV) measurement caused by photoinduced changes in the capacitance gradient [17] can also be a problem. Upon modulated illumination, the KPFM loop indeed measures the time-averaged value of the instantaneous SP weighted by the capacitance gradient [17] instead of the

• spectroscopy on the cathode. In a second step, one can also map a “pseudo surface photovoltage” (SPV*) image by calculating the difference between the signals measured for Δt = 300 and 4.7 ms. It turns out that the SPV* (Figure 9d) and the SPV images (Figure 8g) display a similar contrast. The SPV* image

Review of time-resolved non-contact electrostatic force microscopy techniques with applications to ionic transport measurements

• Aaron Mascaro,
• Yoichi Miyahara,
• Tyler Enright,
• Omur E. Dagdeviren and
• Peter Grütter

Beilstein J. Nanotechnol. 2019, 10, 617–633, doi:10.3762/bjnano.10.62

• . One example of this is in time-resolved Kelvin probe force microscopy (KPFM) experiments that measure the surface photovoltage of a sample as a function of time after a light source is pulsed. This was first implemented by Takihara et al. to measure the photovoltage dynamics of a sample at time scales

A scanning probe microscopy study of nanostructured TiO₂/poly(3-hexylthiophene) hybrid heterojunctions for photovoltaic applications

• Laurie Letertre,
• Roland Roche,
• Olivier Douhéret,
• Hailu G. Kassa,
• Denis Mariolle,
• Nicolas Chevalier,
• Łukasz Borowik,
• Philippe Dumas,
• Benjamin Grévin,
• Roberto Lazzaroni and
• Philippe Leclère

Beilstein J. Nanotechnol. 2018, 9, 2087–2096, doi:10.3762/bjnano.9.197

• monolayer of poly(3-hexylthiophene) (P3HT) functionalized with carboxylic groups (–COOH). Through a joint analysis of the photovoltaic properties at the nanoscale by photoconductive-AFM (PC-AFM) and surface photovoltage imaging, we investigated the physical mechanisms taking place locally during the

Numerical analysis of single-point spectroscopy curves used in photo-carrier dynamics measurements by Kelvin probe force microscopy under frequency-modulated excitation

• Pablo A. Fernández Garrillo,
• Benjamin Grévin and
• Łukasz Borowik

Beilstein J. Nanotechnol. 2018, 9, 1834–1843, doi:10.3762/bjnano.9.175

• useful technique that, when implemented under frequency-modulated excitation, can be used to investigate the surface photovoltage decay, thus providing access to the photo-carrier dynamics [3][4][5][6][7][8][9][10][11]. A common aspect among all KPFM frequency-modulated spectroscopy techniques is that in

• supplied to the system and VOC decays until the charge equilibrium state is reached. The surface photovoltage (SPV), which can be seen as a local measurement of VOC in semiconductors [12], has been studied using KPFM under modulated illumination. Indeed, the investigation of the SPV evolution as a function

• of a frequency-modulated excitation source can be used to access the photo-carrier dynamics in organic, inorganic and hybrid semiconductors [3][4][5][6][7][8][9][13]. In short, as depicted in Figure 1, FMI-KPFM consist of the measurement of a surface photovoltage by KPFM (time response between a few

Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• du Parc 20, B7000 Mons, Belgium 10.3762/bjnano.9.161 Abstract In this work, methylammonium lead tribromide (MAPbBr3) single crystals are studied by noncontact atomic force microscopy (nc-AFM) and Kelvin probe force microscopy (KPFM). We demonstrate that the surface photovoltage and crystal

• . Keywords: carrier lifetime; ion migration; Kelvin probe force microscopy (KPFM); noncontact atomic force microscopy (nc-AFM); organic–inorganic hybrid perovskites; photostriction; single crystals; surface photovoltage (SPV); time-resolved surface photovoltage; Introduction Organic–inorganic hybrid

• the surface potential probed by KPFM. It is now clear that a complex interplay exists between the charge carrier populations, traps, and mobile ions. Despite all the progress made, interpreting the surface potential (SP) and surface photovoltage (SPV) contrasts recorded by KPFM on polycrystalline lead

Artifacts in time-resolved Kelvin probe force microscopy

• Sascha Sadewasser,
• Nicoleta Nicoara and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2018, 9, 1272–1281, doi:10.3762/bjnano.9.119

• simplest approach, time-dependent changes in the CPD are observed in real time in a point measurement following an excitation pulse. Sadewasser et al. [13] studied light-induced changes in a CuGaSe2 semiconductor used in photovoltaic applications. The authors measured the surface photovoltage (SPV) – the

Kelvin probe force microscopy of nanocrystalline TiO₂ photoelectrodes

• Alex Henning,
• Gino Günzburger,
• Res Jöhr,
• Yossi Rosenwaks,
• Biljana Bozic-Weber,
• Catherine E. Housecroft,
• Edwin C. Constable,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2013, 4, 418–428, doi:10.3762/bjnano.4.49

• . Although the nanocrystalline TiO2 photoelectrode of a DSC consists of sintered nanoparticles, there are few studies on the nanoscale properties. We focus on the microscopic work function and surface photovoltage (SPV) determination of TiO2 photoelectrodes using Kelvin probe force microscopy in combination

• ); surface photovoltage (SPV); titanium dioxide (TiO2); Introduction Dye-sensitized solar cells (DSCs) provide a promising low-cost, high-efficiency third-generation photovoltaic concept based on the spectral sensitization of a nanoporous wide bandgap semiconductor [1][2]. In the past two decades DSCs have

• ]. Although a DSC photoelectrode consists of a nanostructured TiO2, there are few microscopic studies [17]. Surface photovoltage (SPV) spectroscopy is a non-destructive and sensitive method for determining surface potential changes upon illumination, identifying surface states, and extracting material

Junction formation of Cu₃BiS₃ investigated by Kelvin probe force microscopy and surface photovoltage measurements

• Fredy Mesa,
• William Chamorro,
• William Vallejo,
• Robert Baier,
• Thomas Dittrich,
• Alexander Grimm,
• Martha C. Lux-Steiner and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2012, 3, 277–284, doi:10.3762/bjnano.3.31

• distribution for In2S3 compared to that of CdS and ZnS. For In2S3 and CdS buffer layers the KPFM experiments indicate negatively charged Cu3BiS3 grain boundaries resulting from the deposition of the buffer layer. Macroscopic measurements of the surface photovoltage at variable excitation wavelength indicate

• good structural and optical properties [5][6]. Recently, the potential of the Cu3BiS3/In2S3 heterojunction was investigated by surface photovoltage (SPV) and Hall-effect measurements, showing a passivation of surface defect states in the Cu3BiS3 by the In2S3 buffer layer and the formation of a

• agreement with our previous measurements [7], from which we drew conclusions toward an effective passivation of the Cu3BiS3 surface by the In2S3 buffer layer. Defining the surface photovoltage as the difference in work function between the dark and the illuminated state (SPV = Φdark − Φlight), we can