Layer-by-Layer Assembled Perovskite/Polymer Photoelectrochemical Devices with Enhanced Performance and Stability.

Organic-inorganic hybrid perovskites (OIHPs) offer a promising pathway for the development of low-cost and efficient solar hydrogen production systems. Despite remarkable advancements, poor chemical stability of the OIHPs in aqueous environments limits their practical applications. Herein, we design a photoelectrochemical (PEC) device consisting of layer-by-layer assembled P(VDF-TrFE)/CHNHPbBr (MAPbBr) hybrid films that simultaneously achieve efficient and stable solar water splitting.

Nonvolatile Control of Valley Polarized Emission in 2D WSe-AlScN Heterostructures.

Achieving robust and electrically controlled valley polarization in monolayer transition metal dichalcogenides (ML-TMDs) is a frontier challenge for realistic valleytronic applications. Theoretical investigations show that the integration of 2D materials with ferroelectrics is a promising strategy; however, an experimental demonstration has remained elusive. Here, we fabricate ferroelectric field-effect transistors using a ML-WSe channel and an AlScN (AlScN) ferroelectric dielectric and experimentally demonstrate efficient tuning as well as non-volatile control of valley polarization.

Valley-Polarized Interlayer Excitons in 2D Chalcogenide-Halide Perovskite-van der Waals Heterostructures.

Interlayer excitons (IXs) in two-dimensional (2D) heterostructures provide an exciting avenue for exploring optoelectronic and valleytronic phenomena. Presently, valleytronic research is limited to transition metal dichalcogenide (TMD) based 2D heterostructure samples, which require strict lattice (mis) match and interlayer twist angle requirements. Here, we explore a 2D heterostructure system with experimental observation of spin-valley layer coupling to realize helicity-resolved IXs, without the requirement of a specific geometric arrangement, i.

Electrode Engineering in Halide Perovskite Electronics: Plenty of Room at the Interfaces.

Contact engineering is a prerequisite for achieving desirable functionality and performance of semiconductor electronics, which is particularly critical for organic-inorganic hybrid halide perovskites due to their ionic nature and highly reactive interfaces. Although the interfaces between perovskites and charge-transporting layers have attracted lots of attention due to the photovoltaic and light-emitting diode applications, achieving reliable perovskite/electrode contacts for electronic devices, such as transistors and memories, remains as a bottleneck. Herein, a critical review on the elusive nature of perovskite/electrode interfaces with a focus on the interfacial electrochemistry effects is presented.

Halide Perovskites: A New Era of Solution-Processed Electronics.

Organic-inorganic mixed halide perovskites have emerged as an excellent class of materials with a unique combination of optoelectronic properties, suitable for a plethora of applications ranging from solar cells to light-emitting diodes and photoelectrochemical devices. Recent works have showcased hybrid perovskites for electronic applications through improvements in materials design, processing, and device stability. Herein, a comprehensive up-to-date review is presented on hybrid perovskite electronics with a focus on transistors and memories.

Recent Advances in Semiconductor-Graphene and Semiconductor-Ferroelectric/Ferromagnetic Nanoheterostructures for Efficient Hydrogen Generation and Environmental Remediation.

Semiconductor heterostructures have attracted intensive research attention during the past few years owing to their great potential for energy and environmental remediation related applications. Effective optical absorption and efficient separation of photogenerated charge carriers are among the key factors for achieving high efficiency in a photocatalytic process. This mini-review summarizes state-of-the-art activities in designing nanosemiconductor heterostructures using multifunctional semiconductors for solar-to-hydrogen conversion and degradation of organic pollutants.

Growth of Doped SrTiO Ferroelectric Nanoporous Thin Films and Tuning of Photoelectrochemical Properties with Switchable Ferroelectric Polarization.

Ferroelectric polarization is an intriguing physical phenomenon for tuning charge-transport properties and finds application in a wide range of optoelectronic devices. So far, ferroelectric materials in a planar geometry or chemically grown nanostructures have been used. However, these structural architectures possess serious disadvantages such as small surface areas and structural defects, respectively, leading to reduced performance.

Giant Humidity Effect on Hybrid Halide Perovskite Microstripes: Reversibility and Sensing Mechanism.

Despite the exceptional performance of hybrid perovskites in photovoltaics, their susceptibility to ambient factors, particularly humidity, gives rise to the well-recognized stability issue. In the present work, microstripes of CHNHPbI are fabricated on flexible substrates, and they exhibit much larger response to relative humidity (RH) levels than continuous films and single crystals. The resistance of microstripes decreases by four orders of magnitude on changing the RH level from 10 to 95%.

Low field magneto-tunable photocurrent in CoFeO nanostructure films for enhanced photoelectrochemical properties.

Efficient solar to hydrogen conversion using photoelectrochemical (PEC) process requires semiconducting photoelectrodes with advanced functionalities, while exhibiting high optical absorption and charge transport properties. Herein, we demonstrate magneto-tunable photocurrent in CoFeO nanostructure film under low applied magnetic fields for efficient PEC properties. Photocurrent is enhanced from ~1.

Effect of graphene nanofillers on the enhanced thermoelectric properties of BiTe nanosheets: elucidating the role of interface in de-coupling the electrical and thermal characteristics.

In this report, we investigate the effect of graphene nanofillers on the thermoelectric properties of BiTe nanosheets and demonstrate the role of interface for enhancing the overall figure of merit (ZT) ∼ 53%. The enhancement in the ZT is obtained due to an increase in the electrical conductivity (∼111%) and decrease in the thermal conductivity (∼12%) resulting from increased conducting channels and phonon scattering, respectively at the interfaces between graphene and BiTe nanosheets. A detailed analysis of the thermal conductivity reveals ∼4 times decrease in the lattice thermal conductivity in contrast to ∼2 times increase in the electronic thermal conductivity after the addition of graphene.

Very High Surface Area Mesoporous Thin Films of SrTiO Grown by Pulsed Laser Deposition and Application to Efficient Photoelectrochemical Water Splitting.

Very high surface area, self-assembled, highly crystalline mesoporous SrTiO (STO) thin films were developed for photoelectrochemical water splitting. Much improved performance of these mesoporous films compared to planar STO thin films and any other form of STO such as single crystal samples and nanostructures was demonstrated. The high performance resulted from very large surface area films and optimization of carrier concentration.