Monocrystalline InP Thin Films with Tunable Surface Morphology and Energy Band gap.

InP is currently being used in various (opto)electronic and energy device applications. However, the high cost of InP substrates and associated epitaxial growth techniques has been huge impediments for its widespread use. Here, large-area monocrystalline InP thin films are demonstrated a convenient cracking method, and the InP thin films show material properties identical to their bulk counterparts.

Engineering III-V Semiconductor Nanowires for Device Applications.

III-V semiconductor nanowires offer potential new device applications because of the unique properties associated with their 1D geometry and the ability to create quantum wells and other heterostructures with a radial and an axial geometry. Here, an overview of challenges in the bottom-up approaches for nanowire synthesis using catalyst and catalyst-free methods and the growth of axial and radial heterostructures is given. The work on nanowire devices such as lasers, light emitting nanowires, and solar cells and an overview of the top-down approaches for water splitting technologies is reviewed.

InGaAsP as a Promising Narrow Band Gap Semiconductor for Photoelectrochemical Water Splitting.

While photoelectrochemical (PEC) water splitting is a very promising route toward zero-carbon energy, conversion efficiency remains limited. Semiconductors with narrower band gaps can absorb a much greater portion of the solar spectrum, thereby increasing efficiency. However, narrow band gap (∼1 eV) III-V semiconductor photoelectrodes have not yet been thoroughly investigated.

15% Efficiency Ultrathin Silicon Solar Cells with Fluorine-Doped Titanium Oxide and Chemically Tailored Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) as Asymmetric Heterocontact.

In order to achieve a high performance-to-cost ratio to photovoltaic devices, the development of crystalline silicon (c-Si) solar cells with thinner substrates and simpler fabrication routes is an important step. Thin-film heterojunction solar cells (HSCs) with dopant-free and carrier-selective configurations look like ideal candidates in this respect. Here, we investigated the application of n-type silicon/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) HSCs on periodic nanopyramid textured, ultrathin c-Si (∼25 μm) substrates.

Ultrathin TaO electron-selective contacts for high efficiency InP solar cells.

Heterojunction solar cells with transition-metal-oxide-based carrier-selective contacts have been gaining considerable research interest owing to their amenability to low-cost fabrication methods and elimination of parasitic absorption and complex semiconductor doping process. In this work, we propose tantalum oxide (Ta2O5) as a novel electron-selective contact layer for photo-generated carrier separation in InP solar cells. We confirm the electron-selective properties of Ta2O5 by investigating band energetics at the InP-Ta2O5 interface using X-ray photoelectron spectroscopy.

Exploiting defects in TiO inverse opal for enhanced photoelectrochemical water splitting.

In this work, we report on defects generation in TiO inverse opal (IO) nanostructures by electrochemical reduction in order to increase photocatalytic activity and improve photoelectrochemical (PEC) water splitting performance. Macroporous structures, such as inverse opals, have attracted a lot of attention for energy-related applications because of their large surface area, interconnected pores, and ability to enhance light-matter interaction. Photocurrent density of electrochemically reduced TiO-IO increased by almost 4 times, compared to pristine TiO-IO photoelectrodes.

Perovskite Photovoltaic Integrated CdS/TiO Photoanode for Unbiased Photoelectrochemical Hydrogen Generation.

Photoelectrolysis of water using solar energy into storable and environment-friendly chemical fuel in the form of hydrogen provides a potential solution to address the environmental concerns and fulfill future energy requirements in a sustainable manner. Achieving efficient and spontaneous hydrogen evolution in water using solar light as the only energy input is a highly desirable but a difficult target. In this work, we report perovskite solar cell integrated CdS-based photoanode for unbiased photoelectrochemical hydrogen evolution.

Photoelectrochemical studies of InGaN/GaN MQW photoanodes.

The research interest in photoelectrochemical (PEC) water splitting is ever growing due to its potential to contribute towards clean and portable energy. However, the lack of low energy band gap materials with high photocorrosion resistance is the primary setback inhibiting this technology from commercialisation. The ternary alloy InGaN shows promise to meet the photoelectrode material requirements due to its high chemical stability and band gap tunability.

Improved photoelectrochemical performance of GaN nanopillar photoanodes.

In this work, we report on the photoelectrochemical (PEC) investigation of n-GaN nanopillar (NP) photoanodes fabricated using metal organic chemical vapour deposition and the top-down approach. Substantial improvement in photocurrents is observed for GaN NP photoanodes compared to their planar counterparts. The role of carrier concentration and NP dimensions on the PEC performance of NP photoanodes is further elucidated.

Applications of atomic layer deposition in solar cells.

Atomic layer deposition (ALD) provides a unique tool for the growth of thin films with excellent conformity and thickness control down to atomic levels. The application of ALD in energy research has received increasing attention in recent years. In this review, the versatility of ALD in solar cells will be discussed.

Photon upconversion in hetero-nanostructured photoanodes for enhanced near-infrared light harvesting.

A hetero-nanostructured photoanode with enhanced near-infrared light harvesting is developed for photo-electrochemical cells. By spatially coating upconversion nanoparticles and quantum dot photosensitizers onto TiO2 inverse opal, this architecture allows direct irradiation of upconversion nanoparticles to emit visible light that excites quantum dots for charge separation. Electrons are injected into TiO2 with minimal carrier losses due to continuous electron conducting interface.

Homogeneous photosensitization of complex TiO₂ nanostructures for efficient solar energy conversion.

TiO₂ nanostructures-based photoelectrochemical (PEC) cells are under worldwide attentions as the method to generate clean energy. For these devices, narrow-bandgap semiconductor photosensitizers such as CdS and CdSe are commonly used to couple with TiO₂ in order to harvest the visible sunlight and to enhance the conversion efficiency. Conventional methods for depositing the photosensitizers on TiO₂ such as dip coating, electrochemical deposition and chemical-vapor-deposition suffer from poor control in thickness and uniformity, and correspond to low photocurrent levels.

Atomic layer deposition for nanofabrication and interface engineering.

Atomic layer deposition (ALD) provides a tool for conformal coating on high aspect-ratio nanostructures with excellent uniformity. It has become a technique for both template-directed nanofabrications and engineering of surface properties. This Feature Article highlights the application of ALD in selected fields including photonics, SERS and energy materials.

Quantum-dot-sensitized TiO2 inverse opals for photoelectrochemical hydrogen generation.

A new nanoarchitecture photoelectrode design comprising CdS quantum-dot-sensitized, optically and electrically active TiO(2) inverse opals is developed for photoelectrochemical water splitting. The photoelectrochemical performance shows high photocurrent density (4.84 mA cm(-2) at 0 V vs.