Regulating Charge and Exciton Distribution in High-Performance Hybrid White Organic Light-Emitting Diodes with n-Type Interlayer Switch

The interlayer(IL) plays a vital role in hybrid white organic light-emitting diodes(WOLEDs); however,only a negligible amount of attention has been given to n-type ILs. Herein, the n-type IL, for the first time,has been demonstrated to achieve a high efficiency, high color rendering index(CRI), and low voltage trade-off.The device exhibits a maximum total efficiency of 41.5 lm W^(-1), the highest among hybrid WOLEDs with n-type ILs. In addition, high CRIs(80–88) at practical luminances(C1000 cd m^(-2)) have been obtained, satisfying the demand for indoor lighting. Remarkably, a CRI of 88 is the highest among hybrid WOLEDs. Moreover, the device exhibits low voltages, with a turn-on voltage of only 2.5 V([1 cd m^(-2)), which is the lowest among hybrid WOLEDs. The intrinsic working mechanism of the device has also been explored; in particular, the role of n-type ILs in regulating the distribution of charges and excitons has been unveiled. The findings demonstrate that the introduction of n-type ILs is effective in developing high-performance hybrid WOLEDs.

Bioaerosol emissions variations in large-scale landfill region and their health risk impacts

Landfills are widely complained about due to the long-term odor and landfill gas emissions for local residents,while the bioaerosols are always neglected as another threat to on-site workers.In this study,bioaerosols samples were collected from the typical operation scenes in the large-scale modern landfill,and the emission levels of airborne bacteria,pathogenic species,and fungi were quantified and co-related.The corresponding exposure risks were assessed based on the average daily dose via inhalation and skin contact.It was found that the levels of culturable bacteria and fungi in all landfill samples were around 33–22778 CFU/m3 and 8–450 CFU/m3,and the active-working landfill area and the covered area were the maximum and minimum emission sources,respectively,meaning that the bioaerosols were mainly released from the areas related with the fresh waste operation.Acinetobacter sp.,Massilia sp.,Methylobacterium-Methylorubrum sp.and Noviherbaspirillum sp.were the main bacterial populations,with a percentage of 42.56%,89.82%,70.24%and 30.20%respectively in total bioaerosols measured.With regards to the health risk,the health risks via inhalation were the main potential risks,with four orders of magnitude higher than that of skin contact.Active-working area showed the critical point for non-carcinogenic risks,with a hazard quotient of 1.68,where 80 m protection distance is recommended for on-site worker protection,plus more careful protection measures.