Esko I. Kauppinen’s research while affiliated with The University of Tokyo and other places

... Modern skyscrapers now increasingly use glass in facades, while semitransparent solar cells with a high-power conversion efficiency (PCE) and high average visible light transmittance (AVT; over 20%) [2] are promoting the development of power glass and sustainable buildings. Among the existing PV technologies, perovskite solar cells (PSCs) have attracted significant attention because of their adjustable bandgap and color, high PCE, low cost, and flexibility [3][4][5]. Semitransparent perovskite solar cells (PSCs) can be constructed by substituting the opaque metal electrode, but the primary challenge associated with balancing the power conversion efficiency (PCE) and optical transmittance lies in the development of high-quality perovskite films and minimizing the energy lost in devices. ...

Reference:

Fabrication of Bifacial-Modified Perovskites for Efficient Semitransparent Solar Cells with High Average Visible Transmittance

... [258] Alternative selective filtration techniques were developed using silicon sealant and high pressure for the fabrication of 2D nanotube structures in various shapes, for instance, concentric circles and spiral zones, for optical applications. [531,532] The fourth level is paramount for scaling as it provides not only new devices (for example, diffraction elements, [258] gratings, [642] or heaters [643] ) but ready-to-use industrial components for FETs, solar cells, transparent sensors, etc. [644,645] The fifth level of nanotube organization (dealing with the interaction between films) is the least explored for CNT films or aerogels. [646] A few works published to date describe www.advancedsciencenews.com www.advmat.de ...

Reference:

Aerosol CVD Carbon Nanotube Thin Films: From Synthesis to Advanced Applications: A Comprehensive Review

... New experiments are focusing on the role of temperature in suppressing coherence between droplets [19,20] opening the way to the study of the finite temperature phase diagram. On the other hand, a supersolid phase in the sense predicted by Andreev and Lifshitz [1], namely a condensate of zero-point vacancies, has been observed in a single layer of 3 He adsorbed on a carbon nanotube [21,22]. On the theory side, while usually ultracold dilute Bose gases are very well described by the Gross-Pitaevskii (GP) theory, the dipolar cluster and supersolid states require the inclusion of the repulsive Lee-Huang-Yang correction in the GP equation (a.k.a. ...

Reference:

Supersolid phase in two-dimensional soft-core bosons at finite temperature

... Pristine CNTs typically undergo p-doping at ambient conditions due to oxygen adsorption, increasing hole concentration. [200,201] Exposure to electron acceptors such as NO 2 gas, a p-type dopant, further increases hole concentration and conductivity, [325,326,327] while electron donors such as NH 3 , an n-type dopant, decrease conductivity. [328,329] CNT diameter and chirality significantly influence gas adsorption and doping. ...

Reference:

Aerosol CVD Carbon Nanotube Thin Films: From Synthesis to Advanced Applications: A Comprehensive Review

... In this work, we have focused on the changes that occur in the resonance Raman spectra of SWCNT thin films as a result of their treatments. Figure 3 [38], which show the evolution of peak parameters related to doping effects and the influence of applied pressure on mixed-chirality SWCNT film, respectively. ...

Reference:

Temperature-dependent parameters of spatially inhomogeneous heterojunctions single-walled carbon nanotubes/Si

... While cold storage (e.g., -80°C) stabilized Ti 3 C 2 T x for over 39 weeks, it is energy-intensive [18]. Compelling MXenes in organic solvents isolated them from water, improving the chemical stability but impairing physical dispersity and complicating re-dispersion in water for subsequent applications [19]. Similarly, covalent surface modifications with agents such as silane [4], protein [20], diazonium [21], and organophosphate passivated defects/ edges on Ti 3 C 2 T x but irreversibly altered its interfacial charge properties in water, compromising electrochemical performance. ...

Reference:

Achieving colloidal stability of diluted MXene dispersions through corrosion inhibition strategy with sodium tartrate

... The Raman signal is collected using the same objective lens, focused into a 230 μm core fiber, and transmitted to a spectrometer (Jobin-Yvan, FNR640) equipped with a TE-cooled CCD (Andor, Newton). 64 Soft XAS and XES are carried out at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory on beamline 8.0.1. using the iRIXS endstation. ...

Reference:

Thermal Conversion of Ultrathin Nickel Hydroxide for Wide Band Gap 2D Nickel Oxides

... For example, D. Polli et al. successfully used three independent, synchronized non-collinear OPAs to generate a pump pulse at 520 nm and two probe pulses in the visible and near-infrared regions, highlighting the existence and significance of conical intersections in visual photochemistry [13]. Nonetheless, the generation of multiple wavelength ultrafast pulses through multi-oscillator systems involves complex optical path designs [14], leading to increased costs, difficulties in system adjustment, and challenges in achieving precise pulse synchronization. This highlights the pressing need for single-cavity high-peak-power multi-wavelength laser sources. ...

Reference:

Quad-wavelength synchronously mode-locked bulk laser based on heterogeneous composite crystal with Fabry-Perot resonant structure

... Therefore, for the Er 3+ -Yb 3+ ion pair, the up-conversion luminescence intensity of the sample is significantly enhanced because the process can significantly increase the utilization rate of Er 3+ ions for 1550 nm photons. [44][45][46][47][48][49][50][51][52][53] Since we do not observe the reverse energy transfer between Ho 3+ -Yb 3+ ion pairs, the up-conversion luminescence intensity of the samples was significantly quenched due to the cross-relaxation between the Ho 3+ -Yb 3+ ions. The schematic diagram of the reverse energy transfer between the ions in Fig. 17 can well summarize the process of the reverse energy transfer between the Er 3+ -Ho 3+ -Yb 3+ ions. ...

Reference:

Modulation of phosphor luminescence performance by high concentration self-sensitization of Er and Ho–Yb ion co-doping under 1550 nm excitation

... Mode-locked fiber lasers have attracted great interest from researchers due to their advantages of high pulse energy, short pulse duration, minimum alignment requirement, and low maintenance. [1][2][3] Up to now, mode-locked fiber lasers have been widely applied in the fields of industrial processing, medical diagnosis and treatment, optical fiber communication, and terahertz optics. [4][5][6] Compared to the active mode-locking realized by inserting a modulator or injecting an external pulse into the fiber cavity to actively modulate the light wave, the passive mode-locking is simpler and more efficient, which incorporates a saturable absorber (SA) into the laser cavity to generate ultrashort pulses. ...

Reference:

Generation of high-energy self-mode-locked pulses in a Tm-doped fiber laser