Organolead triiodide perovskite (CH3NH3PbI3) as a light-sensitive material has attracted extensive attention in optoelectronics. The reported perovskite photodetectors (PDs) mainly focus on the individual, which limits their spatial imaging applications. Uniform perovskite networks combining transparency and device performance were synthesized on poly(ethylene terephthalate) (PET) by controlling perovskite crystallization. Photodetector arrays based on above network were fabricated to demonstrate the potential for image mapping. The trade-off between the PD performance and transparency was systematically investigated and the optimal device was obtained from 30 wt % precursor concentration. The switching ratio, normalized detectivity, and equivalent dark current derived shot noise as the critical parameters of PD arrays reached 300, 1.02 × 10(12) Jones, and 4.73 × 10(-15)A Hz(-1/2), respectively. Furthermore, the PD arrays could clearly detect spatial light intensity distribution, thus demonstrating its preliminary imaging function. The perovskite network PD arrays fabricated on PET substrates could also conduct superior flexibility under wide angle and large number of bending. For the common problem of perovskite optoelectronics in stability, the perovskite networks sheathed with hydrophobic polymers greatly enhanced the device stability due to the improved interface contacts, surface passivation, and moisture isolation. Taking into consideration transparency, flexibility, imaging and stability, the present PD arrays were expected to be widely applied in visualized portable optoelectronic system.
The transitionmetal dichalcogenides‐based phototransistors have demonstrated high transport mobility but are limited to poor photoresponse, which greatly blocks their applications in optoelectronic fields. Here, light sensitive PbS colloidal quantum dots (QDs) combined with 2D WSe2 to develop hybrid QDs/2D‐WSe2 phototransistors for high performance and broadband photodetection are utilized. The device shows a responsivity up to 2 × 105 A W–1, which is orders of magnitude higher than the counterpart of individual material‐based devices. The detection spectra of hybrid devices can be extended to near infrared similar to QDs' response. The high performance of hybrid 0D‐2D phototransistor is ascribed to the synergistic function of photogating effect. PbS QDs can efficiently absorb the input illumination and 2D WSe2 supports a transport expressway for injected photocarriers. The hybrid phototransistors obtain a specific detectivity over 1013 Jones in both ON and OFF state in contrast to the depleted working state (OFF) for other reported QDs/2D phototransistors. The present device construction strategy, photogating enhanced performance, and robust device working conditions contain high potential for future optoelectronic devices.
Background Recent studies indicated that females have a lower morbidity, severe cases rate, mortality and better outcome than those of male. However, it remained to be addressed why this was the case. Methods and findings To find the factors that potentially protect females from COVID-19, we recruited all confirmed patients hospitalized at three branches of Tongji Hospital (n=1902) from January 28 to March 8, 2020, and analyzed the correlation between menstrual status (n=509,including 68 from Mobile Cabin Hospital)/female hormones (n=78)/ cytokines related to immunity and inflammation(n=263), and the severity/clinical outcomes in female patients under 60 years of age.Non-menopausal female patients had milder severity and better outcome compared with age-matched men (p<0.01/p<0.01). Menopausal patients had longer hospitalization times than non-menopausal patients ( hazard ratio [HR], 1.91; 95% confidence interval [CI], 1.06-3.46,p= 0.033). Both anti-müllerian hormone (AMH) and estradiol (E2) showed a negative correlation with severity of infection (AHR=0.146/0.304, 95%CI = [0.026-0.824]/[0.092-1.001], p=0.029/0.05). E2 levels were negatively correlated with IL-2R, IL-6, IL-8 and TNFα in luteal phase (Pearson Correlation=-0.592, -0.558, -0.545, -0.623; p=0.033, 0.048, 0.054, 0.023), and with C3 in follicular phase (Pearson Correlation=-0.651; p=0.030). Conclusion Menopause is an independent risk factor for female COVID-19 patients. AMH and E2 are potential protective factors, negatively correlated with COVID-19’s severity, among which E2 is attributed to its regulation of cytokines related to immunity and inflammation. Hormone supplement might be a potential therapy for COVID-19 patients.
Cu(In,Ga)Se2 (CIGS) is considered a promising photovoltaics material due to its excellent properties and high efficiency. However, the complicated deep defects (such as InCu or GaCu) in the CIGS layer hamper the development of polycrystalline CIGS solar cells. Numerous efforts have been employed to passivate these defects which distributed in the grain boundary and the CIGS/CdS interface. In this work, we implemented an effective Ag substituting approach to passivate bulk defects in CIGS absorber. The composition and phase characterizations revealed that Ag was successfully incorporated in the CIGS lattice. The substituting of Ag could boost the crystallization without obviously changing the band gap. The C–V and EIS results demonstrated that the device showed enlarged Wd and beneficial carrier transport dynamics after Ag incorporation. The DLTS result revealed that the deep InCu defect density was dramatically decreased after Ag substituting for Cu. A champion Ag-substituted CIGS device exhibited a remarkable efficiency of 15.82%, with improved V OC of 630 mV, J SC of 34.44 mA/cm2, and FF of 72.90%. Comparing with the efficiency of an unsubstituted CIGS device (12.18%), a Ag-substituted CIGS device exhibited 30% enhancement.
Antimony sulfide (Sb2S3) as a wide‐bandgap, nontoxic, and stable photovoltaic material reveals great potential for the uppermost cells in Si‐based tandem cell stacks. Sb2S3 solar cells with a compatible process, acceptable cost, and high efficiency therefore become the mandatory prerequisites to match silicon bottom cells. The performance of vacuum processed Sb2S3 device is pinned by bulk and interfacial recombination. Herein, a thermally treated TiO2 buffer layer induces quasiepitaxial growth of vertical orientation Sb2S3 absorber overcoming interface defects and absorber transport loss. Such novel growth could pronouncedly improve the open‐circuit voltage (Voc) due to the superior interface quality and intraribbon transport. The epitaxial rough Sb2S3 surface shows a texturized‐like morphology. It is optimized by tuning the grain sizes to form strong light trapping effect, which further enhances the short‐circuit current density (Jsc) with a 16% improvement. The final optimal device with high stability obtains a power conversion efficiency of 5.4%, which is the best efficiency for full‐inorganic Sb2S3 solar cells. The present developed quasiepitaxy strategy supports a superior interface, vertical orientation, and surface light trapping effect, which provides a new perspective for efficient noncubic material thin film solar cells.
Objective: This study was intended to investigate the relationship between COVID-19 disease and ovarian function in reproductive-aged women.Methods: Female COVID-19 patients of reproductive age were recruited between January 28 and March 8, 2020 from Tongji Hospital in Wuhan. Their baseline and clinical characteristics, as well as menstrual conditions, were recorded. Differentials in ovarian reserve markers and sex hormones (including anti-Müllerian hormone [AMH], follicle-stimulating hormone [FSH], the ratio of FSH to luteinizing hormone [LH], estradiol [E2], progesterone [P], testosterone [T], and prolactin [PRL] were compared to those of healthy women who were randomly selected and individually matched for age, region, and menstrual status. Uni- and multi-variable hierarchical linear regression analyses were performed to identify risk factors associated with ovarian function in COVID-19 women.Results: Seventy eight patients agreed to be tested for serum hormone, of whom 17 (21.79%) were diagnosed as the severe group and 39 (50%) were in the basal level group. Menstrual status (P = 0.55), menstrual volumes (P = 0.066), phase of menstrual cycle (P = 0.58), and dysmenorrhea history (P = 0.12) were similar without significant differences between non-severe and severe COVID-19 women. Significant lower serum AMH level/proportion (0.19/0.28 vs. 1.12 ng/ml, P = 0.003/0.027; AMH ≤ 1.1 ng/ml: 75/70.4 vs. 49.7%, P = 0.009/0.004), higher serum T (0.38/0.39 vs. 0.22 ng/ml, P < 0.001/0.001) and PRL (25.43/24.10 vs. 12.12 ng/ml, P < 0.001/0.001) levels were observed in basal level and the all-COVID-19 group compared with healthy age-matched control. When adjusted for age, menstrual status and parity variations in multivariate hierarchical linear regression analysis, COVID-19 disease was significantly associated with serum AMH (β = −0.191; 95% CI: −1.177–0.327; P = 0.001), T (β = 0.411; 95% CI: 11.154–22.709; P < 0.001), and PRL (β = 0.497; 95% CI: 10.787–20.266; P < 0.001), suggesting an independent risk factor for ovarian function, which accounted for 3.2% of the decline in AMH, 14.3% of the increase in T, and 20.7% of the increase in PRL.Conclusion: Ovarian injury, including declined ovarian reserve and reproductive endocrine disorder, can be observed in women with COVID-19. More attention should be paid to their ovarian function under this pandemic, especially regarding reproductive-aged women.Clinical Trial Number: ChiCTR2000030015.
Sb 2 S 3 has attracted great research interest very recently as a promising absorber material for thin film photovoltaics because of their unique optical and electrical properties, binary compound and easy synthesis. Sb 2 S 3 planar solar cells from evaporation method without hole-transport layer (HTM) assistance suffer from sulfur deficit vacancy and high back contact barrier. Herein, we developed a postsurface selenization treatment to Sb 2 S 3 thin film in order to improve the device performance. The XRD, Raman, and UV−vis spectra indicated the treated film kept the typical characters of Sb 2 S 3 . TEM/EELS mapping of treated Sb 2 S 3 film revealed that only surface adjacent section was partly selenized and formed Sb 2 (S x Se 1−x ) 3 alloy. In addition, XPS results further unfolded that there was trace selenium doping in the bulk of Sb 2 S 3 film. The treated HTM-free Sb 2 S 3 based solar cells were fabricated and an improved efficiency of 4.17% was obtained. The obtained V OC of 0.714 V was the highest and the power conversion efficiency also reached the top value among HTM-free planar Sb 2 S 3 solar cells. The nonencapsulated device exhibited high stability. After storing in ambient air for up to 100 days, the device could maintain 90% efficiency. Systematic materials and device characterizations were implemented to investigate the improvement mechanism for postsurface selenization. The back alloying could suppress the rear contact barrier to improve the fill factor and carrier extraction capability. The bulk Se-doping helped to passivate the interface and bulk defects so as to improve the CdS/Sb 2 S 3 heterojunction quality and enhance the long-wavelength photon quantum yield. The robust treatment method with multifunctional effect holds great potential for new chalcogenide thin film solar cell optimization.
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