Figure 13. a) ST-OSC image with AgNWs cathode and PH1000 anode. Reproduced with permission. [125] Copyright 2014,American Chemical Society. b) The schematic diagram of hydrogen bond and van der Waals bond between D-PEDOT:PSS and PET interface. Reproduced with permission. [132] Copyright 2020, Wiley-VCH. c) Transmittance spectrum of foldable transparent device with D-PEDOT:PSS transporting layer. Reproduced with permission. [132] Copyright 2020, Wiley-VCH. d) Normalized PCE of foldable transparent device after bending for 1000 times. Reproduced with permission. [132] Copyright 2020, Wiley-VCH. e) Preparation procedure for ST-OSCs with all-graphene electrodes. Reproduced with permission. [127] Copyright 2014, American Chemical Society. f ) Schematic illustration of sequential coating and chemical interaction on the surface of a P3HT film during printing of PEDOT:PSS/IL composite electrodes. Reproduced with permission. [131]

Realization of state‐of‐the art efficiencies in organic photovoltaics (OPV) generally relies on using toxic halogenated solution processing to arrive at the desired nanomorphology and optoelectronic responses, whereas the photovoltaic performance in nonhalogenated solution (NHS)‐based OPVs is yet nonsatisfactory, mainly related to the difficulty of morphological control. Herein, a conceptual approach of donor‐dispersed planar heterojunction (DD‐PHJ) for improving the regulation of phase morphology and photovoltaic behaviors in NHS‐processed OPVs is proposed, afforded by dispersing an ordered liquid crystal guest donor BTR‐Cl into the nonfullerene acceptor host with sequential film deposition. The combined investigation shows that the inclusion of BTR‐Cl plays a regulatory role in enhancing the crystallization, intermolecular donor/acceptor miscibility, and homogeneity in the donor–acceptor phase separation along vertical direction, which is conducive to improved charge transfer and reduced photovoltage loss. Of importance, the described DD‐PHJ approach is applicable to representative OPV material systems, leading to a champion efficiency of 18.21% in devices prepared with NHS. This work provides a promising prospect toward high‐efficiency and green solution‐processed OPV devices.

The SARS-CoV-2 virus is deadly, contagious, can cause COVID-19 disease, and endangers public health and safety. The development of SARS-CoV-2 inactivation technology is crucial and imminent in current pandemic period. Neutron radiation is usually used to sterilize viruses because neutron radiation is 10 times more effective than gamma-rays in inactivating viruses. In this work we established a closed SARS-CoV-2 inactivation container model by the Monte Carlo method and simulated the inactivation performance by using several different neutrons sources. To study the effects of inactivation container factors, including the reflector thickness, the type of the reflector material, the SARS-CoV-2 layer area and the distance from the radiation source on the energy deposition of a single neutron particle in SARS-CoV-2 sample, we simulated the neutron energy deposition on a SARS-CoV-2 sample. The simulation results indicate that the saturated thicknesses of reflector materials for graphite, water and paraffin are approximately 30 cm, 15 cm, and 10 cm, respectively, and the energy deposition (radiation dose) becomes larger when the SARS-CoV-2 layer area is smaller and the SARS-CoV-2 layer is placed closer to the neutron source. The calculated single-neutron energy deposition on 10 × 10 cm2 SARS-CoV-2 layer is about 3.0059 × 10−4 MeV/g with graphite as the reflection layer, when the 14 MeV neutron source intensity is 1012 n/s and the SARS-CoV-2 layer is 5 cm away from the neutron source. If the lethal dose of SARS-CoV-2 is assumed as the IAEA recommended reference dose, 25 kGy, the SARS-CoV-2 could be decontaminated in about 87 min, and the sterilization time could be less than 52s if the 14 MeV neutron intensity is increased to 1014 n/s.

Silicon Photomultiplier (SiPM) is a sensor that can detect low-light signals lower than the single-photon level. In order to study the properties of neutrinos at a low detection threshold and low radioactivity experimental background, a low-temperature CsI neutrino coherent scattering detector is designed to be read by the SiPM sensor. Less thermal noise of SiPM and more light yield of CsI crystals can be obtained at the working temperature of liquid nitrogen. The breakdown voltage (Vbd) and dark count rate (DCR) of SiPM at liquid nitrogen temperature are two key parameters for coherent scattering detection. In this paper, a low-temperature test is conducted on the mass-produced ON Semiconductor J-Series SiPM. We design a cryogenic system for cooling SiPM at liquid nitrogen temperature and the changes of operating voltage and dark noise from room to liquid nitrogen temperature are measured in detail. The results show that SiPM works at the liquid nitrogen temperature, and the dark count rate drops by six orders of magnitude from room temperature (120 kHz/mm2) to liquid nitrogen temperature (0.1 Hz/mm2).

Molecular doping is an effective means to tune the optoelectronic properties of organic semiconductors. Despite its versatility, its application in bulk heterojunction (BHJ) organic solar cells (OSCs) is still limited, especially blend‐cast doping. Difficulties in desolving molecular dopants in weakly polar solvents have led to the formation of undesired structures, with relatively high concentrations of dopants affecting the bicontinuous BHJ morphology. Bilayer OSCs are stacked structures with sequential deposition of donor and acceptor films, which make important contributions to the fine tuning of morphology and balanced charge transport. The sequential deposition of thin films in bilayer devices organically facilitates the sequential doping of pure donor polymers by dopants. The sequential doping of the dopant at the interface between the donor and the acceptor can efficiently improve the carrier mobility and the charge transfer between the donor and the acceptor without damaging the quality of the film, thus improving the device performance efficiently. With three different dopants F4TCNQ, F6TCNNQ, and BCF, sequential interfacial doping in bilayer devices is found to be a versatile and effective method to improve device performance. Making this simple doping strategy promising for high‐performance bilayer OSCs, it is evaluated as a promising alternative to BHJ OSCs.