Role of the Optical–Acoustic Phonon Interaction in the Ultrafast Cooling Process of CVD Graphene

Suppressing the Trapping Process by Interfacial Charge Extraction in Antimony Selenide Heterojunctions

Blue low-threshold room-temperature stimulated emission from thermostable perovskite nanocrystals glasses through controlling crystallization

Subwavelength-Polarized Quasi-Two-Dimensional Perovskite Single-Mode Nanolaser

Nonlinear optical properties of CsPbClxBr3-x nanocrystals embedded glass

Hot Carrier Transfer in graphene/PtSe2 Heterostructure Tuned by Built-in Electric Field

<p>Van der Waals heterojunction involving graphene (Gr) with transition metal dichalcogenides (TMDs) is regard as a promising structure for their outstanding performance in optical and optoelectronic response. The electron-hole thermalization has been deemed to be the main reason for the sub-bandgap-excitation charge transfer from Gr to TMDs. However, the role of the intricate interlayer interaction of the Gr and the TMDs still require intensive investigation. Here, we have investigated the photocarrier dynamics in 5-layer PtSe₂/Gr heterojunction by using time-resolved optical pump and terahertz probe spectroscopy. Interestingly, after photoexcitation, electron transfer from PtSe₂ to Gr in PtSe₂/Gr/substrate heterojunction has been demonstrated successfully, by contrast, no observable charge transfer occurs in the Gr/PtSe₂/substrate heterostructure. The prominent difference for the different stacking sequence between Gr and PtSe₂ can be ascribed to the effective built-in field introduced by fused silica substrate. A physical picture accounting for built-in electric field introduced by substrate has been proposed to interpret the charge transfer process in the TMD/Gr heterostructure–the substrate built-in electric field plays a dominated role for controlling the charge transfer pathway in the TMDs/Gr heterojunction. This study not only shed the light to the substrate engineering but also provide a new insight into the dynamic in Gr/TMDs heterojunction, which provides a new method to optimize the performance of photodetection. </p>

Surface Ligand Engineering for CsPbBr 3 Quantum Dots Aiming at Aggregation Suppression and Amplified Spontaneous Emission Improvement

Ultrafast Charge Generation Enhancement in Nanoscale Polymer Solar Cells with DIO Additive

We study the ultrafast photoexcitation dynamics in PBDTTT-C-T (P51, poly(4,8-bis(5-(2-ethylhexyl)-thiophene-2-yl)-benzo[1,2-b:4,5-b′]dithiophene-alt-alkylcarbonyl-thieno[3,4-b]thiophene)) film (~100 nm thickness) and PBDTTT-C-T:PC71BM (P51:PC71BM, phenyl-C71-butyric-acid-methyl ester) nanostructured blend (∼100 nm thickness) with/without DIO(1,8-diiodooctane) additives with sub-10 fs transient absorption (TA). It is revealed that hot-exciton dissociation and vibrational relaxation could occur in P51 with a lifetime of ~160 fs and was hardly affected by DIO. However, the introduction of DIO in P51 brings a longer lifetime of polaron pairs, which could make a contribution to photocarrier generation. In P51:PC71BM nanostructured blends, DIO could promote the Charge Transfer (CT) excitons and free charges generation with a ~5% increasement in ~100 fs. Moreover, the dissociation of CT excitons is faster with DIO, showing a ~5% growth within 1 ps. The promotion of CT excitons and free charge generation by DIO additive is closely related with active layer nanomorphology, accounting for Jsc enhancement. These results reveal the effect of DIO on carrier generation and separation, providing an effective route to improve the efficiency of nanoscale polymer solar cells.

Ultrastable CsPbBr 3 Perovskite Quantum Dot and Their Enhanced Amplified Spontaneous Emission by Surface Ligand Modification

Intraband Ultrafast Terahertz Conductivity Dynamics in Graphene

Sub-wavelength single-mode all-inorganic perovskite CsPbBr3 nanolaser

Element Selected Spin-Dependent d-d Charge Transfer Transitions in Bi2FeMnO6 Film: An Ultrafast Pump-Probe Study

The ultrafast optical response of the magnetic compound Bi2FeMnO6 (BFMO) is studied through 100–300 K by means of ultrafast transient reflectivity spectroscopy. By using differing pump energy, the optical low spin (LS) transition and high spin (HS) transition in this compound are distinguished as the temperature varies. This charge transfer transition is shown to be spin-dependent and element selected. The ultrafast spin-lattice coupling time also shows the element selected feature, which illustrated the two independent magnetic phase transitions to the antiferromagnet (AFM) Mn–O–Mn and the ferrimagnet (FIM) Mn–O–Fe order, respectively.

Ultrafast electron-phonon coupling and photo-induced strain in the morphotropic phase boundary of BixDy1−xFeO3 films

Ultrafast dynamics and coherent vibrations in zinc chlorin aggregates

Tunable Amplified Spontaneous Emission and Lasing from All-inorganic Perovskite Nanocube