Photonic skins enable a direct and intuitive visualization of various physical and mechanical stimuli with eye-readable colorations by intimately laminating to target substrates. Their development is still at infancy compared to that of electronic skins. Here, an ultra-adaptable, large-area (10 × 10 cm 2 ), multipixel (14 × 14) photonic skin based on a naturally abundant and sustainable biopolymer of a shape-memory, responsive multiphase cellulose derivative is presented. The wearable, multipixel photonic skin mainly consists of a photonic sensor made of mesophase cholesteric hydroxypropyl cellulose and an ultraadaptable adhesive layer made of amorphous hydroxypropyl cellulose. It is demonstrated that with multilayered flexible architectures, the multiphase cellulose derivative-based integrated photonic skin can not only strongly couple to a wide range of biological and engineered surfaces, with a maximum of ≈180 times higher adhesion strengths compared to those of the polydimethylsiloxane adhesive, but also directly convert spatiotemporal stimuli into visible color alterations in the large-area, multipixel array. These colorations can be simply converted into 3D strain mapping data with digital camera imaging.

While 2D transition metal dichalcogenides (TMDs) are promising building blocks for various optoelectronic applications, limitations remain for multilayered TMD‐based photodetectors: an indirect bandgap and a short carrier lifetime by strongly bound excitons. Accordingly, multilayered TMDs with a direct bandgap and an enhanced carrier lifetime are required for the development of various optoelectronic devices. Here, periodically arrayed nanopore structures (PANS) are proposed for improving the efficiency of multilayered p‐WSe2/n‐MoS2 phototransistors. Density functional theory calculations as well as photoluminescence and time‐resolved photoluminescence measurements are performed to characterize the photodetector figures of merit of multilayered p‐WSe2/n‐MoS2 heterostructures with PANS. The characteristics of the heterojunction devices with PANS reveal an enhanced responsivity and detectivity measured under 405 nm laser excitation, which at 1.7 × 104 A W−1 and 1.7 × 1013 Jones are almost two orders of magnitude higher than those of pristine devices, 3.6 × 102 A W−1 and 3.6 × 1011 Jones, respectively. Such enhanced optical properties of WSe2/MoS2 heterojunctions with PANS represent a significant step toward next‐generation optoelectronic applications.

detailed understanding of their photocarrier dynamics remains a challenge, largely due to their large exciton binding energy (on the order of 300 meV) [2] in contrast to conventional III-V semiconductors with relatively small binding energies (around 10 meV). [3] Such a large binding energy arises from carrier quantum confinement and reduced dielectric screening. [2a,b,4] Because of the large exciton binding energy, and combined with the absence of a strong electric field in conventional 2D TMDC-based phototransistors, most of the electron-hole pairs tend to undergo recombination and provide no contribution to the photocurrent. [5] Additionally, such phototransistors largely rely on local Schottky barriers with a small photoresponsive area near the contact metals, which is not a suitable system for manipulating and exploring photocarrier dynamics.To date, several strategies have been proposed to probe photophysics, such as hybrid structures [6] and local chemical doping, [7] but they share common challenges including unintentional doping, inevitable chemical disorder, and a limited photoresponsive active area. Moreover, the internal electric fields in these systems are largely dictated by the inherent The probing of fundamental photophysics is a key prerequisite for the construction of diverse optoelectronic devices and circuits. To date, though, photocarrier dynamics in 2D materials remains unclear, plagued primarily by two issues: a large exciton binding energy, and the lack of a suitable system that enables the manipulation of excitons. Here, a WSe 2 -based phototransistor with an asymmetric split-gate configuration is demonstrated, which is named the "asymmetry field-effect phototransistor" (AFEPT). This structure allows for the effective modulation of the electric-field profile across the channel, thereby providing a standard device platform for exploring the photocarrier dynamics of the intrinsic WSe 2 layer. By controlling the electric field, this work the spatial evolution of the photocurrent is observed, notably with a strong signal over the entire WSe 2 channel. Using photocurrent and optical spectroscopy measurements, the physical origin of the novel photocurrent behavior is clarified and a room-temperature exciton binding energy of 210 meV is determined with the device. In the phototransistor geometry, lateral p-n junctions serve as a simultaneous pathway for both photogenerated electrons and holes, reducing their recombination rate and thus enhancing photodetection. The study establishes a new device platform for both fundamental studies and technological applications.

Atomically thin 2D transition metal dichalcogenides (TMDs) have recently been spotlighted for next‐generation electronic and photoelectric device applications. TMD materials with high carrier mobility have superior electronic properties different from bulk semiconductor materials. 0D quantum dots (QDs) possess the ability to tune their bandgap by composition, diameter, and morphology, which allows for a control of their light absorbance and emission wavelength. However, QDs exhibit a low charge carrier mobility and the presence of surface trap states, making it difficult to apply them to electronic and optoelectronic devices. Accordingly, 0D/2D hybrid structures are considered as functional materials with complementary advantages that may not be realized with a single component. Such advantages allow them to be used as both transport and active layers in next‐generation optoelectronic applications such as photodetectors, image sensors, solar cells, and light‐emitting diodes. Here, recent discoveries related to multicomponent hybrid materials are highlighted. Research trends in electronic and optoelectronic devices based on hybrid heterogeneous materials are also introduced and the issues to be solved from the perspective of the materials and devices are discussed.

The ability of estrogen to modulate the expression of ventral and dorsal striatal dopamine receptors D(1), D(2,) and D(3) was examined in vivo using semi-quantitative in situ hybridization and ligand binding autoradiography. Two-week treatment with subcutaneous pellets of 17beta-estradiol (25 mg) downregulated D(2) dopamine receptor mRNA in both dorsal and ventral striatum (shell and core regions of nucleus accumbens). No significant changes in D(1) or D(3) mRNA expression were detected. Ligand binding autoradiography did not reveal changes in D(1), D(2,) or D(3) receptor protein expression. We also assessed the ability of 17beta-estradiol to regulate D(2) gene promoter activity in NB41A3 neuroblastoma cells that express this gene endogenously using co-transfections with an estrogen receptor expression vector. While a small fragment of the D(2) promoter could be activated 2.5-fold by estrogen, a larger portion of the D(2) gene was not regulated by this treatment. Estrogens do not appear to have a net effect on striatal dopamine receptor expression. The observed downregulation of D(2) receptor mRNA in the dorsal and ventral striatum in vivo could be secondary to the increased striatal dopamine release induced by estrogen. Synapse 34:222-227, 1999. Published 1999 Wiley-Liss, Inc.