Microcavity is an efficient approach to manufacture colorful semitransparent organic solar cells (ST-OSCs) with high color purity by tailoring the transmission spectrum to narrow peaks. However, in this type of colorful semitransparent devices, high power conversion efficiency (PCE) and high peak transmittance are not yet simultaneously achieved. This paper proposes a new type of microcavity structure to achieve colorful ST-OSCs with both high PCE and high peak transmittance, in which a hybrid Au/Ag electrode is used as a mirror and WO3 is used as a spacer layer. First, it is demonstrated that the hybrid Au/Ag electrode mirror brings about an improvement of 7.7 and 5.5% for PCE and peak transmittance, respectively, when compared with those of the reference devices using the Ag electrode mirror. Specifically, the PCE of the optimized devices reaches the satisfactory value of over 9%, and the peak transmittance is over 25%. This value of PCE is the highest one reported so far for the microcavity-based ST-OSCs with the same peak transmittance. Second, it is demonstrated that the second-order resonance of the microcavity can be used to improve the color purity of green ST-OSCs by narrowing the transmission peak, and the combination of the second-order and third-order resonance can be used to construct colorful ST-OSCs with mixed colors. Thus, a novel approach is developed to tune the color of ST-OSCs, which is based on high-order resonance modes of the microcavity.

High‐resolution imaging is at the heart of the revolutionary breakthroughs of intelligent technologies, and it is established as an important approach toward high‐sensitivity information extraction/storage. However, due to the incompatibility between non‐silicon optoelectronic materials and traditional integrated circuits as well as the lack of competent photosensitive semiconductors in the infrared region, the development of ultrabroadband imaging is severely impeded. Herein, the monolithic integration of wafer‐scale tellurene photoelectric functional units by exploiting room‐temperature pulsed‐laser deposition is realized. Taking advantage of the surface plasmon polaritons of tellurene, which results in the thermal perturbation promoted exciton separation, in situ formation of out‐of‐plane homojunction and negative expansion promoted carrier transport, as well as the band bending promoted electron–hole pair separation enabled by the unique interconnected nanostrip morphology, the tellurene photodetectors demonstrate wide‐spectrum photoresponse from 370.6 to 2240 nm and unprecedented photosensitivity with the optimized responsivity, external quantum efficiency and detectivity of 2.7 × 107 A W−1, 8.2 × 109% and 4.5 × 1015 Jones. An ultrabroadband imager is demonstrated and high‐resolution photoelectric imaging is realized. The proof‐of‐concept wafer‐scale tellurene‐based ultrabroadband photoelectric imaging system depicts a fascinating paradigm for the development of an advanced 2D imaging platform toward next‐generation intelligent equipment.

Taking advantages of the dangling-bondfree surface, excellent in-plane carrier mobility, pronounced quantum confinement effect, thickness/strain-sensitive physical properties, outstanding mechanical flexibility, and strong light-matter interactions, 2DMs have demonstrated enormous potential in the realm of photo detection. [2][3][4][5] For example, in 2016, Koppens et al. prepared an ultrafast photodetector based on a vertical graphene/ MoSe 2 /graphene sandwich structure. [6] Since the transport path of photocarriers is down to a few molecule layers, the transit time is extremely limited. As a result, the response time of the device with a MoSe 2 channel thickness of 2.2 nm is merely 5.5 ps. In 2020, Maiti et al. achieved the expansion of effective wavelength range of 2DM photodetectors by leveraging strain engineering. [7] The bandgap of 4%-strained 2D MoTe 2 markedly shrinks by ≈0.24 eV as compared to unstrained MoTe 2 (from 1.04 to 0.8 eV). As a result, the strained 2D MoTe 2 photodetector demonstrates distinct photoresponse to illumination of telecommunication wavelengths. Recently, by exploiting graphene as electrodes, connecting lines as well as photosensitive channels, Norris et al. have fabricated "all-graphene" photo detectors, which simultaneously enable light detection and high transparency. [8] Based on such functional units distributed along the optical path, a proof-of-concept single-pixel focal stack light field camera is successfully built and the key operating principle to perform optical ranging is demonstrated.In spite of remarkable progress, the atomic-scale thicknessinduced low light absorption and limited carrier lifetime have been two ever-present limiting factors hindering the effective accumulation of photocarriers and thus curtailing the further breakthrough of the performance of 2DM photodetectors. Various strategies have been developed to address these predicaments. On the one hand, a variety of optical micro-/nanostructures, including plasmonic antenna, [9] optical waveguide, [10] and optical cavity, [11] have been designed to enhance the light harvesting. However, noble metal micro-/nanostructures suffer from high material cost and limited resonant range, while the Low light absorption and limited carrier lifetime are two limiting factors hampering the further breakthrough of the performance of 2D materials (2DMs)-based photodetectors. This study proposes an ingenious dielectric engineering strategy toward boosting the photosensitivity. Periodic dielectric structures (PDSs), including SiO 2 /h-BN, SiO 2 /Al 2 O 3 , and SiO 2 /SrTiO 3 (STO), are exploited to couple with 2D photosensitive channels (denoted as PDS- 2DMs). The responsivity, external quantum efficiency, and detectivity of an optimized SiO 2 /STO (300 nm) -WSe 2 photodetector reach 89081 A W −1 , 2.7 × 10 7 %, and 1.8 × 10 13 Jones, respectively. These performance metrics are orders of magnitude higher than a pristine WSe 2 photodetector, enabling reliable sub-1 pW weak light detection. Based on systematic characterizatio...

A selective-area oxidation strategy is developed to polarize high-symmetry 2D layered materials (2DLMs). The dichroic ratio of the derived O-WS2/WS2 photodetector reaches ∼8, which is competitive among state-of-the-art polarization photodetectors. Finite-different time-domain simulations consolidate that the polarization-sensitive photoresponse is associated with anisotropic spacial confinement, which gives rise to distinct dielectric contrasts for linearly polarized light of various directions and thus the polarization-dependent near-field distribution. Furthermore, selective-area oxidation treatment brings about dual effects, comprising the in situ formation of seamless in-plane WS2 homojunctions by thickness tailoring and the formation of out-of-plane O-WS2/WS2 heterojunctions. As a consequence, the recombination of photocarriers is markedly suppressed, resulting in outstanding photosensitivity with the optimized responsivity, external quantum efficiency, and detectivity of 0.161 A/W, 49.4%, and 1.4 × 1011 Jones for an O-WS2/WS2 photodetector in a self-powered mode. A scheme of multiplexing optical communications is revealed by harnessing the intensity and polarization state of light as independent transmission channels. Furthermore, dynamic encryption by leveraging the polarization state as a secret key is proposed. In the end, broad universality is reinforced through the induction of linear dichroism within 2D WSe2 crystals. On the whole, this study provides an additional perspective on polarization optoelectronics based on 2DLMs.

The extensively explored unary and binary 2D layered materials (2DLMs) based photodetectors suffer from deficiencies of either poor stability, or indistinctive photoswitching, or poor scalability, or low durability to high‐temperature environment. Herein, a two‐step scenario, pulsed laser deposition (PLD) followed by post‐deposition annealing, is developed to produce centimeter‐scale 2D ZnIn2S4 (ZIS) nanofilms. Transport characterizations indicate that the as‐fabricated ZIS photodetectors manifest outstanding photosensitivity with an on/off switching ratio beyond 1000 upon 405 nm illumination. Beyond this, it is revealed that the photoresponse of the ZIS photodetectors increases with increasing channel thickness, where a responsivity of 1.4 A W−1, an external quantum efficiency of 430% and a detectivity of 9.8 × 109 Jones (1 Jones = 1 cm Hz1/2 W–1) are demonstrated with a pulse number of 10 000. In addition, these devices without encapsulation maintain stable within 1900 photoswitching cycles and over a one‐month storage in air. Furthermore, robust photoswitching is demonstrated under an operating temperature up to 150 °C. In summary, all these findings establish that PLD provides a powerful route to produce large‐scale multielement 2DLMs and the PLD‐derived ZIS photodetectors hold grand prospect for photoelectric technologies in specific high‐temperature environments (e.g., the lunar exploration program).