ABSTRACT
Cu2ZnSn(S,Se)4 (CZTSSe) solar cells with low cost and eco-friendly characteristics are attractive as future sources of electricity generation, but low conversion efficiency remains an issue. To improve conversion efficiency, a method of inserting intermediate layers between the CZTSSe absorber film and the Mo back contact is used to suppress the formation of MoSe2 and decomposition of CZTSSe. Among the candidates for the intermediate layer, graphene oxide (GO) and reduced GO have excellent properties, including high-charge mobility and low processing cost. Depending on the type of GO, the solar cell parameters, such as fill factor (FF), were enhanced. Thus, the conversion efficiency of 6.3% was achieved using the chemically reduced GO intermediate layer with significantly improved FF.
ABSTRACT
Quantum dot (QD)-based luminescent down-shifting (LDS) layers were deposited on Cu2ZnSn(S,Se)4 (CZTSSe) solar cells via the drop-casting method. The LDS layers can easily widen the narrow absorption wavelength regions of single-junction solar cells and enable improvement of the short-circuit current. The optical properties of LDS layers deposited on glass and containing different QD contents were analyzed based on their transmittance, reflectance, and absorbance. The absorber films to be used in the CZTSSe solar cells were determined by X-ray diffraction measurements and Raman spectroscopy to determine their crystal structures and secondary phases, respectively. The completed CZTSSe solar cells with LDS layers showed increased ultraviolet responses of up to 25% because of wavelength conversion by the QDs. In addition, the impact of the capping layer, which was formed to protect the QDs from oxygen and moisture, on the solar cell performance was analyzed. Thus, a maximal conversion efficiency of 7.3% was achieved with the 1.0 mL QD condition; furthermore, to the best of our knowledge, this is the first time that LDS layers have been experimentally demonstrated for CZTSSe solar cells.
ABSTRACT
Here, we report the complete genome sequences of two bovine viral diarrhea viruses (BVDVs) (strains 11F011 and 12F004) isolated from brain tissues from nonambulatory (downer) cattle. The complete genomes of strains 11F011 and 12F004 contain 12,287 nucleotides (nt) with a single large open reading frame and 12,301 nt with a single large open reading frame, respectively. Phylogenetic analysis indicated that these strains belong to the BVDV-2a and -1b genotypes, respectively.
ABSTRACT
Here, we report the complete genome sequence of a bovine viral diarrhea virus (BVDV) belonging to genotype 1d, strain 10JJ-SKR, which was isolated from cattle. The complete genome is 12,267 nucleotides (nt) in length, with a single large open reading frame. This is the first report of a BVDV belonging to genotype 1d and will enable further study of the molecular and epidemiological characteristics of this virus.
