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

• defects is responsible for reducing the carrier lifetime, or by the lack of a true ohmic contact between the sample holder and the n-type InP substrate during the KPFM measurement. In the second case, a potential barrier would be present at the metal contact/n-InP substrate interface, which could reduce

Plasmonic nanotechnology for photothermal applications – an evaluation

• A. R. Indhu,
• L. Keerthana and
• Gnanaprakash Dharmalingam

Beilstein J. Nanotechnol. 2023, 14, 380–419, doi:10.3762/bjnano.14.33

• shorter, such as 10–30 fs for Al [74]. Hot carrier lifetime and electron–phonon coupling of selected metals are shown in Figure 10 and Figure 11. From the representation of electron filling for the different materials shown in Figure 10, it can be seen that the carrier lifetimes (depicted by the curvature

High–low Kelvin probe force spectroscopy for measuring the interface state density

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

Beilstein J. Nanotechnol. 2023, 14, 175–189, doi:10.3762/bjnano.14.18

• following equation [25][26]: with The index 0 indicates equilibrium quantities. For low-level injection, at which the excess minority carrier density is low compared to the equilibrium majority carrier density, the net generation/recombination rate RSRH is dominated by the hole (minority carrier) lifetime

• τp in n-type semiconductors and the electron (minority carrier) lifetime τn in p-type semiconductors as follows: where σn and σp are the capture cross sections for electrons and holes, respectively, vth is the thermal velocity, and Nit is the concentration of interface states. These equations

• density. For an n-type Si semiconductor at room temperature, the hole (minority carrier) lifetime τp as a function of electron (majority carrier) density n has been experimentally investigated and is reported to be less than 2.5 × 10−5 s for low carrier densities n < 5 × 1017 cm−3 [26]. Additionally, for

Near-infrared photoactive Ag-Zn-Ga-S-Se quantum dots for high-performance quantum dot-sensitized solar cells

• Roopakala Kottayi,
• Ilangovan Veerappan and
• Ramadasse Sittaramane

Beilstein J. Nanotechnol. 2022, 13, 1337–1344, doi:10.3762/bjnano.13.110

• ][32]. Figure 4d shows the PL decay spectrum of AZGSSe QDs fitted with a biexponential function (), where τ1 and τ2 are the carrier life times, and α1 and α2 are the relative amplitudes of the respective carrier lifetime. The average life (τs) of the AZGSSe QDs was calculated to be 42.64 ns [33

Recent progress in perovskite solar cells: the perovskite layer

• Xianfeng Dai,
• Ke Xu and
• Fanan Wei

Beilstein J. Nanotechnol. 2020, 11, 51–60, doi:10.3762/bjnano.11.5

• because of the unique morphology, which resulted in long carrier lifetime and low defect density. Of course, this precursor solution can be used for slot-die coating to fabricate high-quality PCSs at a high throughput rate. The combination of this special coating solution and the slot-die-coating

• suitable boiling point, effectively accelerated the crystallization rate of the corresponding 2DRP perovskite. This yielded smooth, dense films with an efficiency of 12.15% and long charge-carrier lifetime, high photoluminescence intensity, low trap density and improved stability. However, the PCE of 2D

Nontoxic pyrite iron sulfide nanocrystals as second electron acceptor in PTB7:PC₇₁BM-based organic photovoltaic cells

• Olivia Amargós-Reyes,
• José-Luis Maldonado,
• Omar Martínez-Alvarez,
• María-Elena Nicho,
• José Santos-Cruz,
• Juan Nicasio-Collazo,
• Irving Caballero-Quintana and
• Concepción Arenas-Arrocena

Beilstein J. Nanotechnol. 2019, 10, 2238–2250, doi:10.3762/bjnano.10.216

• ][8], a high optical absorption coefficient (2 × 105 cm−1) [4], high carrier mobility (2 to 80 cm2/Vs) [4][9] and a large charge carrier lifetime (200 ps) [10]. Therefore, FeS2 nanoparticles (NPs) can be a good alternative for PV applications [11]. Nanostructures of FeS2 have been used as counter

CuInSe₂ quantum dots grown by molecular beam epitaxy on amorphous SiO₂ surfaces

• Henrique Limborço,
• Pedro M.P. Salomé,
• Rodrigo Ribeiro-Andrade,
• Jennifer P. Teixeira,
• Nicoleta Nicoara,
• Kamal Abderrafi,
• Joaquim P. Leitão,
• Juan C. Gonzalez and
• Sascha Sadewasser

Beilstein J. Nanotechnol. 2019, 10, 1103–1111, doi:10.3762/bjnano.10.110

• defects are important sources of radiative and non-radiative recombination affecting the optoelectronic properties of CIS quantum dots (QDs), such as photo-generated carrier lifetime and photoluminescence [15]. We ascribe the increase in the photoluminescence related to the nanodots to the passivation of

Contactless photomagnetoelectric investigations of 2D semiconductors

• Marian Nowak,
• Marcin Jesionek,
• Barbara Solecka,
• Piotr Szperlich,
• Piotr Duka and
• Anna Starczewska

Beilstein J. Nanotechnol. 2018, 9, 2741–2749, doi:10.3762/bjnano.9.256

• ) materials in electronic devices require the development of appropriate measuring methods for determining their typical semiconductor parameters, i.e., mobility and carrier lifetime. Among these methods, contactless techniques and mobility extraction methods based on field-effect measurements are of great

•  2c). Figure 3 shows the calculated dependences of the PME magnetic flux on values of material parameters. The is proportional to the square of the carrier lifetime (Figure 3a). Its value increases with increasing μ and reaches its maximum value (Figure 3b). It should be noted that for a stronger

• intensity of illumination (Figure 5c). Such dependences of VPME are characteristic for the case of a carrier lifetime that is independent of the concentration of photogenerated carriers (i.e., for low illumination intensity) in a weak magnetic field [10]. These results agree with the first observations of

Thickness-dependent photoelectrochemical properties of a semitransparent Co₃O₄ photocathode

• Malkeshkumar Patel and
• Joondong Kim

Beilstein J. Nanotechnol. 2018, 9, 2432–2442, doi:10.3762/bjnano.9.228

• in such applications include CuxO [19][29], CdS [30], TiO2 [31], Fe2O3 [32], and BiVO4 [33][34]. To absorb light with Co3O4, an adequately thick film is required. However, the low mobility of photogenerated charge carriers in Co3O4 can result in a low carrier lifetime, which is detrimental for

Lead-free hybrid perovskites for photovoltaics

• Oleksandr Stroyuk

Beilstein J. Nanotechnol. 2018, 9, 2209–2235, doi:10.3762/bjnano.9.207

• accumulate in a surface layer of the HP film exerting a passivating effect and resulting in a longer charge carrier lifetime [102]. The introduction of Ca2+ on the Pb2+ sites of CsPbI3 HP results in a more homogeneous a better contact between the HP and HTL, as well as the surface passivation by a Ca

• carrier lifetime [126]. The solar cells produced from these highly uniform HP layers revealed a negligible hysteresis and no light soaking effect, indicating a largely suppressed recombination. The best PCE was 9%, which is by 50% higher than for similar cells with the HP layer modified by SnF2 [76]. A

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

• access to carrier lifetime at the nanoscale in a wide range of photovoltaic materials. However, some aspects about the data interpretation of techniques based on this approach are still the subject of debate, for example, the plausible presence of capacitance artifacts. Special attention shall also be

• experimental results as additional information about the photo-carrier dynamics of the sample can be gained via the numerical analysis. Keywords: carrier dynamics; carrier lifetime; carrier recombination; Kelvin probe force microscopy; nanostructured photovoltaics; numerical simulations; photo-carrier

• dynamics; Introduction In the past decade, the nanoscale investigation of materials properties has captured the attention of the scientific community, partially due to its crucial importance in the improvement of photovoltaic devices [1][2]. Carrier lifetime, or more broadly speaking, photo-carrier

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

• . 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

• , including a direct band gap, high absorption coefficient, large and balanced carrier mobility, high diffusion length, long carrier lifetime and high photoluminescence quantum yield. Within a few years of their discovery, these materials were successfully used to develop photovoltaic cells [2] with power

• (Figure 5a). In the last years, several works have indeed shown that the effective carrier lifetime in photovoltaic thin films can be quantified by analyzing the dependence of the time-averaged surface potential (SPav) with respect to the modulation frequency (f) of the illumination source [20][34][35][36

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

• various groups for the characterization of organic devices [23][24][25][26] and, by using bias modulation (BM) KPFM, also for the measurement of the minority carrier lifetime in epitaxial Si solar cell materials [27]. In a variation of the bias or light modulation approach, a bias-based pump–probe

• approach (pp-KPFM) was used to measure the charge-carrier dynamics with a time resolution of 2 μs in pentacene-based OFETs [28][29]. Similarly, light-based pp-KPFM was used to measure a charge carrier lifetime in low-temperature grown GaAs of ≈1 ps, currently the best time-resolution that has been

CdSe nanorod/TiO₂ nanoparticle heterojunctions with enhanced solar- and visible-light photocatalytic activity

• Fakher Laatar,
• Hatem Moussa,
• Halima Alem,
• Lavinia Balan,
• Emilien Girot,
• Ghouti Medjahdi,
• Hatem Ezzaouia and
• Raphaël Schneider

Beilstein J. Nanotechnol. 2017, 8, 2741–2752, doi:10.3762/bjnano.8.273

• separation. The interfacial electron transfer between two semiconductors has gained significant interest because the heterojunction improves both the optical absorption in the visible range and the charge separation yield and thus the charge carrier lifetime [3][4][5][6][7][8]. The photocatalytic activity is

Charge injection and transport properties of an organic light-emitting diode

• Peter Juhasz,
• Juraj Nevrela,
• Michal Micjan,
• Miroslav Novota,
• Jan Uhrik,
• Lubica Stuchlikova,
• Jan Jakabovic,
• Ladislav Harmatha and
• Martin Weis

Beilstein J. Nanotechnol. 2016, 7, 47–52, doi:10.3762/bjnano.7.5

• trapping mechanism. At voltages higher than 3 V the rise of current density slows down to J V3 and follows two-carrier space-charge limited conditions (2C-SCLC), where ε is the dielectric constant of the organic film, μe and μh are electron and hole mobilities, respectively, and τ is carrier lifetime [13

Current–voltage characteristics of manganite–titanite perovskite junctions

• Benedikt Ifland,
• Patrick Peretzki,
• Birte Kressdorf,
• Philipp Saring,
• Andreas Kelling,
• Michael Seibt and
• Christian Jooss

Beilstein J. Nanotechnol. 2015, 6, 1467–1484, doi:10.3762/bjnano.6.152

• . Modeling diffusion length determination by EBIC The charge carrier diffusion length, L, is an important parameter to determine the recombination-limited charge transport processes in electronic devices [50]. It is connected to the charge carrier lifetime, τ, and mobility, μ, by the Einstein relation: While

Observation and analysis of structural changes in fused silica by continuous irradiation with femtosecond laser light having an energy density below the laser-induced damage threshold

• Wataru Nomura,
• Tadashi Kawazoe,
• Takashi Yatsui,
• Makoto Naruse and
• Motoichi Ohtsu

Beilstein J. Nanotechnol. 2014, 5, 1334–1340, doi:10.3762/bjnano.5.146

• , and nonlinear polarization reflecting the pulse width of the laser was observed. In contrast, ΔRD, and ΔRE showed temporal broadenings of about several 100 fs. Because these decay times are close to the photogenerated carrier lifetime of silica 150 fs [16][17], it is assumed the temporal changes in