Design and fabrication of vertically aligned single-crystalline Si nanotube arrays and their enhanced broadband absorption properties

Tseng, Yu-Hsiang; Gu, Renpeng; Cheng, Sheng-Tzong

doi:10.1016/j.apsusc.2019.145223

Cited by 10 publications

(6 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The development of electrochemically active, durable, and cost-effective catalysts for the conversion of water (H 2 O) into hydrogen (H 2 ) is beneficial for realizing a carbon-neutral, sustainable society. To achieve this goal, solar-driven water splitting devices have been widely used because they alleviate the electrical energy input required to produce H 2 . − Although highly active catalysts are indispensable for an efficient hydrogen evolution reaction (HER) on the semiconductor surface (light absorber), parasitic light absorption by optically opaque catalysts on the surface of light absorbers reduces the amount of incident photons that reaches them. , Since light must reach the absorber through the catalytic layers to generate charge carriers from excitons, it is important to integrate the catalysts onto the surface of photoelectrodes with controlled spatial distribution for efficient photon management. Otherwise, there will be an unavoidable negative correlation between catalyst loading and photoelectrochemical performance …”

Section: Introductionmentioning

confidence: 99%

Functional Integration of Catalysts with Si Nanowire Photocathodes for Efficient Utilization of Photogenerated Charge Carriers

et al. 2021

View full text Add to dashboard Cite

Low-cost catalysts with high activity and durability are necessary to achieve efficient large-scale energy conversion in photoelectrochemical cell (PEC) systems. An additional factor that governs the construction of photoelectrodes for PECs is the spatial control of the catalysts for efficient utilization of photogenerated charge carriers. Here, we demonstrate spatial decoupling of the light-absorbing and catalytic components in hierarchically structured Si-based photocathodes for the hydrogen evolution reaction (HER). By simply modifying a well-known metal-assisted chemical etching procedure, we fabricated a Si nanowire (NW) array-based photocathode with Ag–Pt catalysts at the base and small amounts of the Pt catalyst at the NW tips. This approach simultaneously mitigates the parasitic light absorption by the catalytic layers and recombination of charge carriers owing to the long transport distance, resulting in improved photoelectrochemical HER performance under simulated AM 1.5G illumination.

show abstract

Section: Introductionmentioning

confidence: 99%

Functional Integration of Catalysts with Si Nanowire Photocathodes for Efficient Utilization of Photogenerated Charge Carriers

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The irregular pore size and nonuniform distribution of the above-mentioned porous substrates may cause dead volume, which results in low volumetric performance. Alternatively, highly ordered nanopillar or nanotube polymer films obtained by means of controlled lithography techniques have become a promising candidate for flexible supercapacitor electrodes. − Although the highly ordered nanostructure and porosity of polymer films with excellent mechanical properties enable the enhancement of the energy storage performance of flexible supercapacitors, the electrochemical performances of capacitance, rate capability, and cycle life should be further improved to develop flexible supercapacitors. In addition, the scalable fabrication of large-area nanostructured active materials on polymer films with controlled pore sizes and 3D structures is a challenge.…”

Section: Introductionmentioning

confidence: 99%

Large-Area and 3D Polyaniline Nanoweb Film for Flexible Supercapacitors with High Rate Capability and Long Cycle Life

Park

Jeong

Kim

et al. 2020

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

Flexible, thin, and lightweight supercapacitors have been regarded as important power sources for portable and wearable electronics; however, these are usually limited by relatively low areal or volumetric performances compared to their gravimetric performance. In this paper, a large-area, thin, and flexible three-dimensional (3D) polyaniline nanoweb film with controlled nanomorphology is reported for the improvement of the areal and volumetric performances of supercapacitors. The 3D nanoweb structure provides large ion accessible active sites, short ion diffusion distance, and enhanced mechanical tolerance during electrochemical reactions. The resulting polyaniline nanoweb film electrodes exhibit a high areal capacitance of 303 mF/cm 2 at 10 mV/s, a high capacitance retention of 73% even at a high scan rate of 1000 mV/s, and long-term cycle stability (98.9% capacitance retention over 10000 cycles). The all-solid-state flexible supercapacitors deliver high device area-specific and volume-specific energy densities of 12.7 μWh/cm 2 and 1.0 Wh/L, respectively.

show abstract

“…In Ref. [35], a lowcost fabrication technology of vertically aligned Si NTs via a wet-etching process with controllable NT thickness was demonstrated. Besides thermoelectrics, the applications of Si-based NTs include biosensors, energy storage, photodetectors, optoelectronics and field-effect transistors [35][36][37][38][39].…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, combination of crystalline silicon and amorphous silica layers allows one to study unusual phonon phenomena related to phonon propagation through heterogeneous crystalline/amorphous media [8,28,43,51]. Although Si-based NTs have been intensively studied during recent years [32][33][34][35][36][37][38][39], their thermal properties remain poorly understood.…”

Section: Introductionmentioning

confidence: 99%

Phonons and Thermal Transport in Si/SiO2 Multishell Nanotubes: Atomistic Study

et al. 2021

View full text Add to dashboard Cite

Thermal transport in the Si/SiO2 multishell nanotubes is investigated theoretically. The phonon energy spectra are obtained using the atomistic lattice dynamics approach. Thermal conductivity is calculated using the Boltzmann transport equation within the relaxation time approximation. Redistribution of the vibrational spectra in multishell nanotubes leads to a decrease of the phonon group velocity and the thermal conductivity as compared to homogeneous Si nanowires. Phonon scattering on the Si/SiO2 interfaces is another key factor of strong reduction of the thermal conductivity in these structures (down to 0.2 Wm−1K−1 at room temperature). We demonstrate that phonon thermal transport in Si/SiO2 nanotubes can be efficiently suppressed by a proper choice of nanotube geometrical parameters: lateral cross section, thickness and number of shells. We argue that such nanotubes have prospective applications in modern electronics, in cases when low heat conduction is required.

show abstract

Design and fabrication of vertically aligned single-crystalline Si nanotube arrays and their enhanced broadband absorption properties

Cited by 10 publications

References 27 publications

Functional Integration of Catalysts with Si Nanowire Photocathodes for Efficient Utilization of Photogenerated Charge Carriers

Functional Integration of Catalysts with Si Nanowire Photocathodes for Efficient Utilization of Photogenerated Charge Carriers

Large-Area and 3D Polyaniline Nanoweb Film for Flexible Supercapacitors with High Rate Capability and Long Cycle Life

Phonons and Thermal Transport in Si/SiO2 Multishell Nanotubes: Atomistic Study

Contact Info

Product

Resources

About