Modelling of novel-structured copper barium tin sulphide thin film solar cells

[EN] In this work, a novel structured Cu2BaSnS4 (CBTS)/ZnS/Zn(O, S) photovoltaic device is proposed. A nontoxic, earth-abundant and auspicious quaternary semiconductor compound copper barium tin sulphide (Cu2BaSnS4) is used as an absorber layer. We propose a novel Zn(O, S) buffer layer for a high-power conversion efficiency (PCE) of CBTS-based thin film photovoltaic cells. Solar cell capacitance simulator software is used for device modelling and simulations are performed under a 1.5 AM illumination spectrum. The proposed device is investigated by means of numerical modelling and optimized the parameters to maximize its efficiency. Promising optimized functional parameters had been achieved from the proposed structure with back surface field layer with a PCE of 18.18%, a fill factor of 83.45%, a short-circuit current of 16.13 mA cm¿2 and an open-circuit voltage of 1.3 V. The promising results give an imperative standard for possible manufacturing of high efficiency, eco-friendly inorganic CBTS-based photovoltaic cells.This work was supported by Ministerio de Economia y Competitividad (ENE2016-77798-C4-2-R) and Generalitat valenciana (Prometeus 2014/044).Hameed, KY.; Baig, F.; Toura, H.; Marí, B.; Beg, S.; Khani, NAK. (2019). Modelling of novel-structured copper barium tin sulphide thin film solar cells. Bulletin of Materials Science. 42(5):1-8. https://doi.org/10.1007/s12034-019-1919-9S18425Ge J, Koirala P, Grice C R, Roland P J, Yu Y, Tan X et al 2017 Adv. Energy Mater. 7 1601803Khattak Y H, Mahmood T, Alam K, Sarwar T, Ullah I and Ullah H 2014 Am. J. Electr. Power Energy Syst. 3 86Steinmann V, Brandt R E and Buonassisi T 2015 Nat. Photonics 9 355Jackson P, Hariskos D, Wuerz R, Kiowski O, Bauer A, Friedlmeier T M et al 2015 Phys. Status Solidi: Rapid. Res. Lett. 9 28Shin D, Saparov B and Mitzi D B 2017 Adv. Energy Mater. 7 1602366Paper C, Le A, Universit D, Universit B, Universit M A, Marchionna S et al 2017 Eur. Photovolt. Sol. Energy Conf. 33 25Khattak Y H, Baig F, Ullah S, Marí B, Beg S and Ullah H 2018 J. Renew. Sustain. Energy 10 033501Fontané X, Izquierdo-Roca V, Saucedo E, Schorr S, Yukhymchuk V O, Valak M Y et al 2012 J. Alloys Compd. 539 190Zhang X, Bao N, Ramasamy K, Wang Y-H A, Yifeng Wang B L and Gupta A 2012 Chem. Commun. 48 4956Adewoyin A D, Olopade M A and Chendo M 2017 Optik—Int. J. Light Electron Opt. 133 122Boutebakh F Z, Zeggar M L, Attaf N and Aida M S 2017 Optik—Int. J. Light Electron Opt. 144 180Ananthakumar S, Ram Kumar J and Moorthy Babu S 2016 Optik—Int. J. Light Electron Opt. 127 10360Jianjun L, Dongxiao W, Xiuling L and Zeng Y 2018 Adv. Sci. 5 1700744Khattak Y H, Baig F, Ullah S, Marí B, Beg S and Ullah H 2018 Optik—Int. J. Light Electron Opt. 164 547Xiao Z, Meng W, Li J V. and Yan Y 2017 ACS Energy Lett. 2 29Shin D, Saparov B, Zhu T, Huhn W P, Blum V and Mitzi D B 2016 Chem. Mater. 28 477Repins I L, Romero M J, Li J V, Wei S-H, Kuciauskas D, Jiang C-S et al 2013 J. Photovoltaics 3 439Zhou H, Hsu W-C, Duan H-S, Bob B, Yang W, Song T-B et al 2013 Energy Environ. Sci. 6 2822Khattak Y H, Baig F, Toura H, Ullah S, Marí B, Beg S et al 2018 Curr. Appl. Phys. 18 633Ge J, Roland P J, Koirala P, Meng W, Young J L, Petersen R et al 2017 Chem. Mater. 29 916Ge J and Yan Y 2017 J. Mater. Chem. C 5 6406Hong F, Lin W, Meng W and Yan Y 2016 Phys. Chem. Chem. Phys. 18 4828Todorov T, Gunawan O and Guha S 2016 Mol. Syst. Des. Eng. 1 370Baig F, Ullah H, Khattak Y H and Mari Soucase B 2016 Int. Ren. Sus. En. Conf. 596, https://doi.org/10.1109/IRSEC.2016.7983899Lin L-Y, Qiu Y, Zhang Y and Zhang H 2016 Chinese Phys. Lett. 33 10780Platzer B C, Törndahl T, Abou-Ras D, Malmström J, Kessler J and Stolt L 2006 J. Appl. Phys. 100 044506Persson C, Platzer-Björkman C, Malmström J, Törndahl T and Edoff M 2006 Phys. Rev. Lett. 97 146403Burgelman M, Nollet P and Degrave S 2000 Thin Solid Films 361 527Khattak Y H, Baig F, Soucase B M and Beg S 2018 Mater. Focus 84 758Simya O K, Mahaboobbatcha A and Balachander K A 2015 Superlattices Microstruct. 82 248Shin D, Zhu T, Huang X, Gunawan O, Blum V and Mitzi D B 2017 Adv. Mater. 29 1Saha U and Alam M K 2018 Phys. Status Solidi: Rapid Res. Lett. 12 1Zhu T, Huhn W P, Wessler G C, Shin D, Saparov B, Mitzi D B et al 2017 Chem. Mater. 29 7868Ge J, Grice C R and Yan Y 2017 J. Mater. Chem. A 5 2920Baig F, Khattak Y H, Marí B, Beg S, Gillani S R and Ahmed A 2018 Optik—Int. J. Light Electron Opt. 170 463Khattak Y H, Baig F, Ullah S, Marí B, Beg S and Gillani S R 2018 Optik—Int. J. Light Electron Opt. 171 45

Spleen-Resident CD4+ and CD4− CD8α− Dendritic Cell Subsets Differ in Their Ability to Prime Invariant Natural Killer T Lymphocytes

One important function of conventional dendritic cells (cDC) is their high capacity to capture, process and present Ag to T lymphocytes. Mouse splenic cDC subtypes, including CD8α+ and CD8α− cDC, are not identical in their Ag presenting and T cell priming functions. Surprisingly, few studies have reported functional differences between CD4− and CD4+ CD8α− cDC subsets. We show that, when loaded in vitro with OVA peptide or whole protein, and in steady-state conditions, splenic CD4− and CD4+ cDC are equivalent in their capacity to prime and direct CD4+ and CD8+ T cell differentiation. In contrast, in response to α-galactosylceramide (α-GalCer), CD4− and CD4+ cDC differentially activate invariant Natural Killer T (iNKT) cells, a population of lipid-reactive non-conventional T lymphocytes. Both cDC subsets equally take up α-GalCer in vitro and in vivo to stimulate the iNKT hybridoma DN32.D3, the activation of which depends solely on TCR triggering. On the other hand, and relative to their CD4+ counterparts, CD4− cDC more efficiently stimulate primary iNKT cells, a phenomenon likely due to differential production of co-factors (including IL-12) by cDC. Our data reveal a novel functional difference between splenic CD4+ and CD4− cDC subsets that may be important in immune responses

Tailored design of NKT-stimulatory glycolipids for polarization of immune responses

Natural killer T (NKT) cell is a distinct population of T lymphocytes that can rapidly release massive amount of Th1 and Th2 cytokines upon the engagement of their T cell receptor with glycolipids presented by CD1d. The secreted cytokines can promote cell-mediated immunity to kill tumor cells and intracellular pathogens, or suppress autoreactive immune cells in autoimmune diseases. Thus, NKT cell is an attractive target for developing new therapeutics to manipulate immune system. The best-known glycolipid to activate NKT cells is α-galactosylceramide (α-GalCer), which has been used as a prototype for designing new NKT stimulatory glycolipids. Many analogues have been generated by modification of the galactosyl moiety, the acyl chain or the phytosphingosine chain of α-GalCer. Some of the analogues showed greater abilities than α-GalCer in polarizing immune responses toward Th1 or Th2 dominance. Among them, several analogues containing phenyl groups in the lipid tails were more potent in inducing Th1-skewed cytokines and exhibited greater anticancer efficacy than α-GalCer. Analyses of the correlation between structure and activity of various α-GalCer analogues on the activation of iNKT cell revealed that CD1d–glycolipid complexes interacted with the same population of iNKT cell expressing similar T-cell receptor Vβ as α-GalCer. On the other hand, those phenyl glycolipids with propensity for Th1 dominant responses showed greater binding avidity and stability than α-GalCer for iNKT T-cell receptor when complexed with CD1d. Thus, it is the avidity and stability of the ternary complexes of CD1d-glycolipid-iNKT TCR that dictate the polarity and potency of immune responses. These findings provide a key to the rationale design of immune modulating glycolipids with desirable Th1/Th2 polarity for clinical application. In addition, elucidation of α-GalCer-induced anergy, liver damage and accumulation of myeloid derived suppressor cells has offered explanation for its lacklustre anti-cancer activities in clinical trials. On other hand, the lack of such drawbacks in glycolipid analogues containing phenyl groups in the lipid tails of α-GalCer coupled with the greater binding avidity and stability of CD1d-glycolipid complex for iNKT T-cell receptor, account for their superior anti-cancer efficacy in tumor bearing mice. Further clinical development of these phenyl glycolipids is warranted

Interferon-γ independent formation of pulmonary granuloma in mice by injections with trehalose dimycolate (cord factor), lipoarabinomannan and phosphatidylinositol mannosides isolated from Mycobacterium tuberculosis

The mechanisms by which pulmonary granuloma formation is caused by administration of mycobacterial glycolipids such as trehalose dimycolate (TDM), lipoarabinomannan (LAM) and phosphatidylinositol mannosides (PIM) were investigated. When peritoneal and alveolar macrophages were stimulated with TDM, LAM and PIM in vitro, TDM exhibited the strongest tumour necrosis factor (TNF)-inducing activity. Responsiveness of macrophages from mice defected Toll-like receptor 4 (TLR4) was much higher than that of the wild-type mice. Although PIM and LAM also had a significant activity, LAM rather than PIM stimulated higher TNF-α production by alveolar macrophage. When mycobacterial glycolipids were injected as water-in-oil-in-water emulsion into mice via the tail vein, development of pulmonary granuloma in response to glycolipids were related closely to their TNF-inducing activity and TDM exhibited the strongest activity. Granuloma formation was observed not only in mice lacking interleukin (IL)-12 signalling but also interferon (IFN)-γ knock-out mice. Granuloma formation caused by glycolipids correlated with TNF-α levels in lungs. Administration of anti-TNF-α monoclonal antibody into TDM-injected IFN-γ knock-out mice decreased in granuloma formation, suggesting that development of pulmonary granuloma by mycobacterial glycolipids such as TDM is due to IFN-γ-independent and TNF-α-dependent pathway

Activation of Vα14(+) Natural Killer T Cells by α-Galactosylceramide Results in Development of Th1 Response and Local Host Resistance in Mice Infected with Cryptococcus neoformans

We examined the effect of α-galactosylceramide (α-GalCer) on the synthesis of gamma interferon (IFN-γ) and local resistance in mice infected intravenously with Cryptococcus neoformans. The level of IFN-γ in serum increased on day 3, reached a peak level on day 7, and decreased to the basal level on day 14 postinfection in mice treated with α-GalCer, while in vehicle-treated mice, no increase was detected at any time points except for a small increase on day 7. Such effects were not observed in NKT-KO mice. In CD4KO mice, minor synthesis of IFN-γ was detected on day 3 in sera but was completely abolished by day 7. The α-GalCer-induced IFN-γ production on day 3 was partially reduced in mice depleted of NK cells by treatment with anti-asialo-GM(1) antibody (Ab). Spleen cells obtained from infected and α-GalCer-treated mice on day 7 produced a large amount of IFN-γ upon restimulation with live organisms, while only a marginal level of production was detected in splenocytes from infected and vehicle-treated mice. Such effects were abolished in CD4KO and NKT-KO mice. Finally, the fungal loads in the lungs and spleen on days 7 and 14 were significantly reduced in α-GalCer-treated mice compared to those in control mice. In NKT-KO mice, local resistance elicited by α-GalCer was completely abolished, although no obvious exacerbation of infection was detected. Furthermore, treatment with anti-IFN-γ monoclonal Ab mostly abrogated the protective effect of this agent. Thus, our results indicated that activation of Vα14(+) NKT cells resulted in an increased Th1 response and local resistance to C. neoformans through production of IFN-γ

α-Galactosylceramide (KRN7000) suppression of chemical- and oncogene-dependent carcinogenesis

Recent studies have revealed significant efficacy of the marine sponge glycolipid, α-galactosylceramide (α-GalCer), in treatment of experimental metastatic cancers, infections, and autoimmune diseases. However, the capacity of α-GalCer to prevent tumor development had never, to our knowledge, been evaluated in mouse models of chemical- and oncogene-dependent carcinogenesis. In this study, we demonstrate that long-term administration of soluble α-GalCer, spanning the time of tumor initiation, inhibits primary tumor formation in three different models: methylcholanthrene-induced sarcomas, mammary carcinomas in Her-2/neu transgenic mice, and spontaneous sarcomas in p53(–)(/)(–) mice. Weekly treatment of mice with α-GalCer maintained lymphoid tissue natural killer cell and T cell activation and elevated serum IFN-γ and IL-4 concentrations. Consistent with the antimetastatic activity of α-GalCer, prevention of methylcholanthrene-induced sarcoma was IFN-γand tumor necrosis factor-related apoptosis-inducing ligand dependent, but not perforin-dependent. Taken together, our results demonstrate that NK1.1(+)αβTCR(+) cell-based immune therapy can inhibit primary tumorigenesis

Relationship between N-cycling communities and ecosystem functioning in a 50-year-old fertilization experiment

International audienceThe relative importance of size and composition of microbial communities in ecosystem functioning is poorly understood. Here, we investigated how community composition and size of selected functional guilds in the nitrogen cycle correlated with agroecosystem functioning, which was defined as microbial process rates, total crop yield and nitrogen content in the crop. Soil was sampled from a 50-year fertilizer trial and the treatments comprised unfertilized bare fallow, unfertilized with crop, and plots with crop fertilized with calcium nitrate, ammonium sulfate, solid cattle manure or sewage sludge. The size of the functional guilds and the total bacterial community were greatly affected by the fertilization regimes, especially by the sewage sludge and ammonium sulfate treatments. The community size results were combined with previously published data on the composition of the corresponding communities, potential ammonia oxidation, denitrification, basal and substrate-induced respiration rates, in addition to crop yield for an integrated analysis. It was found that differences in size, rather than composition, correlated with differences in process rates for the denitrifier and ammonia-oxidizing archaeal and total bacterial communities, whereas neither differences in size nor composition was correlated with differences in process rates for the ammonia-oxidizing bacterial community. In contrast, the composition of nitrate-reducing, denitrifying and total bacterial communities co-varied with primary production and both were strongly linked to soil properties