Handong Li

Strain-free ring-shaped nanostructures by droplet epitaxy for photovoltaic application

Droplet epitaxy is a flexible nanomaterial growth technique and is a potential method to fabricate advanced electronic and optoelectronic devices. Here, we report strain-free GaAs/Al0.33Ga0.67As quantum ring solar cells fabricated by droplet epitaxy technique. Photoluminescence is used to study the electronic structure of the lattice-matched GaAs/Al0.33Ga0.67As quantum ring solar cells. Post-growth thermal annealing is used to improve the optical quality of the solar cell as well as device efficiency. A power conversion efficiency of 1.8% is demonstrated from a prototype quantum ring solar cell. This work opens new opportunities for quantum dot solar cells with strain-free nanostructures.

High Responsivity Photoconductors Based on Iron Pyrite Nanowires Using Sulfurization of Anodized Iron Oxide Nanotubes

Iron pyrite (FeS2) nanostructures are of considerable interest for photovoltaic applications due to improved material quality compared to their bulk counterpart. As an abundant and nontoxic semiconductor, FeS2 nanomaterials offer great opportunities for low-cost and green photovoltaic technology. This paper describes the fabrication of FeS2 nanowire arrays via sulfurization of iron oxide nanotubes at relatively low temperatures. A facile synthesis of ordered iron oxide nanotubes was achieved through anodization of iron foils. Characterization of the iron sulfide nanowires indicates that pyrite structures were formed. A prototype FeS2 nanowire photoconductor demonstrates very high responsivity (>3.0 A/W). The presented method can be further explored to fabricate various FeS2 nanostructures, such as nanoparticles, nanoflowers, and nanoplates.

Laterally aligned quantum rings: From one-dimensional chains to two-dimensional arrays

We present the fabrication of ordered quantum rings by the conversion of partially capped quantum dots. Morphological transformation of quantum dots to quantum rings is demonstrated by partially capping self-assembled quantum dots. Quantum rings have been fabricated on high index surfaces by this growth technique. The lateral ordering of quantum rings is introduced by engineering the strain field of a multi-layer InGaAs superlattice template. By using high index surfaces, the one-dimensional ordering of quantum rings on GaAs (100) surface was observed to evolve into two-dimensional aligned quantum ring arrays.

Field emission from in situ-grown vertically aligned SnO2 nanowire arrays

Vertically aligned SnO2 nanowire arrays have been in situ fabricated on a silicon substrate via thermal evaporation method in the presence of a Pt catalyst. The field emission properties of the SnO2 nanowire arrays have been investigated. Low turn-on fields of 1.6 to 2.8 V/μm were obtained at anode-cathode separations of 100 to 200 μm. The current density fluctuation was lower than 5% during a 120-min stability test measured at a fixed applied electric field of 5 V/μm. The favorable field-emission performance indicates that the fabricated SnO2 nanowire arrays are promising candidates as field emitters.

Tunable semimetallic state in compressive-strained SrIr O 3 films revealed by transport behavior

Orthorhombic

Growth and band alignment of Bi2Se3 topological insulator on H-terminated Si(111) van der Waals surface

\mathrm{SrIr}{\mathrm{O}}_{3}

Bismuth telluride nanostructures: preparation, thermoelectric properties and topological insulating effect

is a typical spin-orbit-coupled correlated metal that shows diversified physical properties under external stimuli. Here the nonlinear Hall effect and weakly temperature-dependent resistance are observed in a

Phase-pure iron pyrite nanocrystals for low-cost photodetectors

\mathrm{SrIr}{\mathrm{O}}_{3}

Site-controlled fabrication of Ga nanodroplets by focused ion beam

film epitaxially grown on a

Silicon-based Nanomaterials

\mathrm{SrTi}{\mathrm{O}}_{3}