Grain engineering of Sb2S3 thin films to enable efficient planar solar cells with high open-circuit voltage

Sb2S3 is a promising environmentally friendly semiconductor for high performance solar cells. But, like many other polycrystalline materials, Sb2S3 is limited by nonradiative recombination and carrier scattering by grain boundaries (GBs). This work shows how the GB density in Sb2S3 films can be significantly reduced from 1068 ± 40 to 327 ± 23 nm µm−2 by incorporating an appropriate amount of Ce3+ into the precursor solution for Sb2S3 deposition. Through extensive characterization of structural, morphological, and optoelectronic properties, complemented with computations, it is revealed that a critical factor is the formation of an ultrathin Ce2S3 layer at the CdS/Sb2S3 interface, which can reduce the interfacial energy and increase the adhesion work between Sb2S3 and the substrate to encourage heterogeneous nucleation of Sb2S3, as well as promote lateral grain growth. Through reductions in nonradiative recombination at GBs and/or the CdS/Sb2S3 heterointerface, as well as improved charge-carrier transport properties at the heterojunction, this work achieves high performance Sb2S3 solar cells with a power conversion efficiency reaching 7.66%. An impressive open-circuit voltage (VOC) of 796 mV is achieved, which is the highest reported thus far for Sb2S3 solar cells. This work provides a strategy to simultaneously regulate the nucleation and growth of Sb2S3 absorber films for enhanced device performance

Grain engineering of Sb2S3 thin films to enable efficient planar solar cells with high open-circuit voltage

Sb2S3 is a promising environmentally friendly semiconductor for high performance solar cells. But, like many other polycrystalline materials, Sb2S3 is limited by nonradiative recombination and carrier scattering by grain boundaries (GBs). This work shows how the GB density in Sb2S3 films can be significantly reduced from 1068 ± 40 to 327 ± 23 nm µm−2 by incorporating an appropriate amount of Ce3+ into the precursor solution for Sb2S3 deposition. Through extensive characterization of structural, morphological, and optoelectronic properties, complemented with computations, it is revealed that a critical factor is the formation of an ultrathin Ce2S3 layer at the CdS/Sb2S3 interface, which can reduce the interfacial energy and increase the adhesion work between Sb2S3 and the substrate to encourage heterogeneous nucleation of Sb2S3, as well as promote lateral grain growth. Through reductions in nonradiative recombination at GBs and/or the CdS/Sb2S3 heterointerface, as well as improved charge-carrier transport properties at the heterojunction, this work achieves high performance Sb2S3 solar cells with a power conversion efficiency reaching 7.66%. An impressive open-circuit voltage (VOC) of 796 mV is achieved, which is the highest reported thus far for Sb2S3 solar cells. This work provides a strategy to simultaneously regulate the nucleation and growth of Sb2S3 absorber films for enhanced device performance

Inequalities for sector matrices and positive linear maps

Ando proved that if A, B are positive definite, then for any positive linear map Φ, it holds Φ(A#λB) ≤ Φ(A)#λΦ(B), where A#λB, 0 ≤ λ ≤ 1, means the weighted geometric mean of A, B. Using the recently defined geometric mean for accretive matrices, Ando’s result is extended to sector matrices. Some norm inequalities are considered as well.&#x0D;  &#x0D;  </jats:p

Inequalities for sector matrices and positive linear maps

Ando proved that if A, B are positive definite, then for any positive linear map Φ, it holds Φ(A#λB) ≤ Φ(A)#λΦ(B), where A#λB, 0 ≤ λ ≤ 1, means the weighted geometric mean of A, B. Using the recently defined geometric mean for accretive matrices, Ando’s result is extended to sector matrices. Some norm inequalities are considered as well. &nbsp; &nbsp

Bacterial Communities in the Feces of Laboratory Reared Gampsocleis gratiosa (Orthoptera: Tettigoniidae) across Different Developmental Stages and Sexes

We used Illumina sequencing of the 16S rDNA V3-V4 region to identify the bacterial community in laboratory-reared G. gratiosa feces across different developmental stages (1st&ndash;7th instar nymph day 0, and 0-, 7-, 14-, and 21-day adult) and sexes. In total, 14,480,559 high-quality reads were clustered into 2982 species-level operational taxonomic units (OTUs), with an average of 481.197 (&plusmn;137.366) OTUs per sample. These OTUs were assigned into 25 phyla, 42 classes, 60 orders, 116 families, 241 genera, and some unclassified groups. Only 21 core OTUs were shared by all samples. The most representative phylum was Proteobacteria, followed by Firmicutes, Bacteroidetes, and Acidobacteria. At the genus level, Kluyvera (387 OTUs), Obesumbacterium (339 OTUs), Buttiauxella (296 OTUs), Lactobacillus (286 OTUs), and Hafnia (152 OTUs) were dominant bacteria. The early-instar nymphs harbored a similar bacterial community with other developmental stages, which contain higher species diversity. Both principal coordinate analysis (PCoA) and non-metric multidimensional scaling analysis (NMDS) failed to provide a clear clustering based on the developmental stages and sexes. Overall, we assume that G. gratiosa transmits bacteria vertically by eating contaminated eggshells, and both developmental stages and sexes had no significant effect on the fecal bacterial community

Bacterial Communities in the Feces of Laboratory Reared Gampsocleis gratiosa (Orthoptera: Tettigoniidae) across Different Developmental Stages and Sexes

We used Illumina sequencing of the 16S rDNA V3-V4 region to identify the bacterial community in laboratory-reared G. gratiosa feces across different developmental stages (1st–7th instar nymph day 0, and 0-, 7-, 14-, and 21-day adult) and sexes. In total, 14,480,559 high-quality reads were clustered into 2982 species-level operational taxonomic units (OTUs), with an average of 481.197 (±137.366) OTUs per sample. These OTUs were assigned into 25 phyla, 42 classes, 60 orders, 116 families, 241 genera, and some unclassified groups. Only 21 core OTUs were shared by all samples. The most representative phylum was Proteobacteria, followed by Firmicutes, Bacteroidetes, and Acidobacteria. At the genus level, Kluyvera (387 OTUs), Obesumbacterium (339 OTUs), Buttiauxella (296 OTUs), Lactobacillus (286 OTUs), and Hafnia (152 OTUs) were dominant bacteria. The early-instar nymphs harbored a similar bacterial community with other developmental stages, which contain higher species diversity. Both principal coordinate analysis (PCoA) and non-metric multidimensional scaling analysis (NMDS) failed to provide a clear clustering based on the developmental stages and sexes. Overall, we assume that G. gratiosa transmits bacteria vertically by eating contaminated eggshells, and both developmental stages and sexes had no significant effect on the fecal bacterial community.</jats:p