The high carrier mobility and long diffusion length of perovskite material have been regarded because of its excellent photovoltaic performance. However, many studies have shown that a diffusion length longer than 1 ...The high carrier mobility and long diffusion length of perovskite material have been regarded because of its excellent photovoltaic performance. However, many studies have shown that a diffusion length longer than 1 μm and higher carrier mobility have no positive effect on the cells' performance. Studies of organic solar cells have demonstrated the existence of an optimal mobility value, while systematic research of the carrier mobility in the PSCs is very rare. To make these questions clear, the effect of carrier mobility on perovskite solar cells' performance is studied in depth in this paper by simulation.Our study shows that the optimal mobility value of the charge transportation layer and absorption layer are influenced by both doping concentration and layer thickness. The appropriate carrier mobility can reduce the carrier recombination rate and enhance the carrier concentration, thus improving the cells' performance. A high efficiency of 27.39% is obtained in the simulated cell with the combination of the optimized parameters in the paper.展开更多
AIM:To investigate the depressive state among the patients with symptomatic vitreous floaters(SVF),as well as its change after SVF removal via vitrectomy surgery.METHODS:Twenty-eight eyes of 28 patients who underwent ...AIM:To investigate the depressive state among the patients with symptomatic vitreous floaters(SVF),as well as its change after SVF removal via vitrectomy surgery.METHODS:Twenty-eight eyes of 28 patients who underwent 27-gauge pars plana vitrectomy(PPV)for SVF were included.Thirty-nine eyes of 39 age-and gendermatched healthy volunteers without SVF were also recruited as a healthy control.Center for Epidemiologic Studies Depression(CES-D)was used to assess volunteers and patients’depression(before and 1 wk after PPV).RESULTS:The CES-D score was 18.3±8.6 for patients,and was 12.4±6.0 for healthy control(P=0.003).Patients were significantly more likely to be in a depressive state(53.6%,defined as CES-D score≥16)than the healthy control(20.5%,P=0.005).For patients with SVF,the CES-D score was negatively correlated with their age(rs=-0.42,P=0.025).After PPV,both the CES-D score(11.9±5.4 vs 18.3±8.6,P<0.001)and proportion of depressive state(18.5%vs 53.6%,P=0.005)were significantly decreased.CONCLUSION:This study suggests that symptoms of vitreous floaters have an apparently negative impact on patients’psychological state.The PPV can effectively relieve the depressive state for patients with SVF.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61704147)the Science Fund from the Education Department of Hebei Province,China(Grant No.QN2017150)
文摘The high carrier mobility and long diffusion length of perovskite material have been regarded because of its excellent photovoltaic performance. However, many studies have shown that a diffusion length longer than 1 μm and higher carrier mobility have no positive effect on the cells' performance. Studies of organic solar cells have demonstrated the existence of an optimal mobility value, while systematic research of the carrier mobility in the PSCs is very rare. To make these questions clear, the effect of carrier mobility on perovskite solar cells' performance is studied in depth in this paper by simulation.Our study shows that the optimal mobility value of the charge transportation layer and absorption layer are influenced by both doping concentration and layer thickness. The appropriate carrier mobility can reduce the carrier recombination rate and enhance the carrier concentration, thus improving the cells' performance. A high efficiency of 27.39% is obtained in the simulated cell with the combination of the optimized parameters in the paper.
基金Supported by Zhejiang Provincial Natural Science Foundation of China(No.LQ18H120004)the Innovation Research Project of the Eye Hospital of Wenzhou Medical University(No.YNCX201308).
文摘AIM:To investigate the depressive state among the patients with symptomatic vitreous floaters(SVF),as well as its change after SVF removal via vitrectomy surgery.METHODS:Twenty-eight eyes of 28 patients who underwent 27-gauge pars plana vitrectomy(PPV)for SVF were included.Thirty-nine eyes of 39 age-and gendermatched healthy volunteers without SVF were also recruited as a healthy control.Center for Epidemiologic Studies Depression(CES-D)was used to assess volunteers and patients’depression(before and 1 wk after PPV).RESULTS:The CES-D score was 18.3±8.6 for patients,and was 12.4±6.0 for healthy control(P=0.003).Patients were significantly more likely to be in a depressive state(53.6%,defined as CES-D score≥16)than the healthy control(20.5%,P=0.005).For patients with SVF,the CES-D score was negatively correlated with their age(rs=-0.42,P=0.025).After PPV,both the CES-D score(11.9±5.4 vs 18.3±8.6,P<0.001)and proportion of depressive state(18.5%vs 53.6%,P=0.005)were significantly decreased.CONCLUSION:This study suggests that symptoms of vitreous floaters have an apparently negative impact on patients’psychological state.The PPV can effectively relieve the depressive state for patients with SVF.
