Monolayer transition-metal dichalcogenide crystals (TMDC) can be combined with other functional materials, such as organic molecules, to form a wide range of heterostructures tailorable properties. Although number works have shown that ultrafast charge transfer (CT) occur at organic/TMDC interfaces, conditions would facilitate the separation interfacial CT excitons into free carriers remain unclear. Here, time-resolved and steady-state photoemission spectroscopy are used study potential...

Since the discovery of graphene and its outstanding chemical, optical, mechanical properties, other layered materials have been fiercely hunted for throughout various techniques. Thanks to their van der Waals interaction, acting as weak glue, different types with mismatched lattices can be stacked high quality interfaces. The properties resulting multilayer structures tuned by choice materials, layer thicknesses, sequence in which they are arranged. This opens possibility a large array...

High quality and stable electrical contact between metal two-dimensional materials, such as transition dichalcogenides, is a necessary requirement that has yet to be achieved in order successfully exploit the advantages these materials offer electronics optoelectronics. MoTe2, owing its phase changing property, can potentially solution. A recent study demonstrated metallic of MoTe2 connects semiconducting with very low resistance. To utilize this property connect other it important achieve...

We report a combined theoretical and experimental study on photocarrier dynamics in monolayer phosphorene bulk black phosphorus.

We observed ultrafast charge transfer between distorted $1T\text{\ensuremath{-}}{\mathrm{ReS}}_{2}$ with anisotropic in-plane electronic and optical properties $2H\text{\ensuremath{-}}{\mathrm{WS}}_{2}$ that is isotropic. Heterostructures of monolayer ${\mathrm{ReS}}_{2}$/monolayer ${\mathrm{WS}}_{2}$ bilayer were fabricated by mechanical exfoliation dry techniques. Significant photoluminescence quenching in the heterostructures indicates efficient transfer. In femtosecond transient...

The recently discovered two-dimensional materials can be used to fabricate multilayer heterostructures. Interlayer charge transfer is a key process in such heterostructures as it enable emergent optoelectronic properties. Efficient interlayer van der Waals has been observed by femtosecond transient absorption and steady-state optical spectroscopy measurements, based on measuring the carrier distribution. Here, we show that second harmonic generation allows direct probing of electric field...

We report observations of a strong thickness dependence for charge transfer (CT) from MoSe2 to MoS2, as evidenced by transient absorption measurements. By time-resolving CT monolayers (1Ls) MoS2 flakes varying thicknesses, including 1L, bilayer (2L), and trilayer (3L), we find that the time is several picoseconds in 1L-MoSe2/3L-MoS2 heterostructure, which much longer than 1L-MoSe2/1L-MoS2 1L-MoSe2/2L-MoS2 heterostructures. In addition, recombination lifetime interlayer excitons 1L/3L...

Transient absorption measurement reveals ultrafast charge transfer from crystalline to amorphous two-dimensional semiconductors.

We report three-pulse photodope-pump-probe measurements on photocarrier dynamics in semiconducting transition metal dichalcogenide monolayers of ${\mathrm{MoS}}_{2}$, ${\mathrm{WS}}_{2}$, ${\mathrm{MoSe}}_{2}$, and ${\mathrm{WSe}}_{2}$. The samples are fabricated by metal-organic chemical vapor deposition mechanical exfoliation techniques characterized photoluminescence spectroscopy. In the time-resolved measurement, first photodoped a prepulse, which injects background photocarriers various...

Forming van der Waals multilayer structures with two-dimensional materials is a promising new method for material discovery. The weak interlayer interaction without atomic correspondence relaxes lattice matching requirement and allows formation of high-quality interfaces virtually any combination materials. However, the nature also makes it challenging to harness emergent properties such Previous studies have indicated that in transition metal dichalcogenide bilayer heterostructures, charge...

An all-optical approach to control interlayer charge transfer and exciton dynamics is demonstrated using transition metal dichalcogenide heterostructures of ${\mathrm{MoSe}}_{2}/{\mathrm{MoS}}_{2}$ ${\mathrm{MoSe}}_{2}/{\mathrm{WS}}_{2}$ as examples. In the three-pulse pump-probe experiments, a pulse injects photocarriers produces an electric field due separation. A pump excites new carriers their under influence control-injected time-resolved by measuring differential reflectance third...

Semiconducting molybdenum ditelluride has emerged as a promising transition-metal dichalcogenide with number of novel properties. In particular, its bandgap in infrared range makes it an attractive candidate for ultrathin and high-performance optoelectronic applications. Dynamical properties photocarriers play key role determining performance such devices. We report experimental study on spatiotemporal dynamics both monolayer bulk MoTe2. Transient absorption measurement reflection geometry...

We report an experimental study on charge transfer properties of mixed-dimensional heterostructures formed by zero-dimensional PbS quantum dots and two-dimensional transition metal dichalcogenides. Monolayers ${\mathrm{MoSe}}_{2}$ ${\mathrm{MoS}}_{2}$ were fabricated mechanical exfoliation chemical vapor deposition techniques, respectively. with diameters 2.3 5 nm synthesized a hot-injection method characterized optical absorption spectroscopy ultraviolet photoemission spectroscopy. The...

We report a combined experimental and computational study on the charge transfer properties of heterostructures formed by monolayer 1T′-ReS2 fluorinated zinc phthalocyanine, F8ZnPc. Two-dimensional (2D) ReS2 flakes were exfoliated from bulk crystals, an F8ZnPc film with thickness 4 nm was thermally deposited ReS2. Density functional theory shows that two materials form type-II band alignment. In transient absorption measurements, photocarriers are selectively excited in monitored found holes...

We report the properties of sputtered/co-evaporated thin film iron pyrite as back contact interface layer CdS/CdTe solar cells. In our study we have compared performance sputter-deposited CdTe devices which utilized either a Cu/Au contact, or an FeS <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> /Cu/Au contact. Comparing best each type, has improved V xmlns:xlink="http://www.w3.org/1999/xlink">OC</sub> by ~16 mV, to 816 and FF ~4.7%...