Hybrid CIGS-Cobalt Quaterpyridine Photocathode with Backside Illumination: A New Paradigm for Solar Fuel Production.

Chalcogenide-based thin-film solar cell optimized for rear illumination and used for CO reduction is presented. Central to this innovation is a thinner, Cu(In,Ga)S chalcopyrite absorber coated with a robust metallic top layer, which potentially surpasses the performance of conventional front-illuminated designs. Using cobalt quaterpyridine molecular catalyst, photocurrent densities for CO reduction exceeding 10 mA/cm at 0.

Evidence of the Ambipolar Behavior of Mo Cluster Iodides in All-Inorganic Solar Cells: A New Example of Nanoarchitectonic Concept.

Ambipolar materials such as carbon nanotubes, graphene, or 2D transition metal chalcogenides are very attractive for a large range of applications, namely, light-emitting transistors, logic circuits, gas sensors, flash memories, and solar cells. In this work, it is shown that the nanoarchitectonics of inorganic Mo cluster-based iodides enable to form thin films exhibiting photophysical properties that enable their classification as new members of the restricted family of ambipolar materials. Thus, the electronic properties of the ternary iodide Cs[{MoI}I] and those of thin films of the aqua-complex-based compound [{MoI}I(HO)]·HO were investigated through an in-depth photoelectrochemical study.

Electronic Structure of the CdS/Cu(In,Ga)Se Interface of KF- and RbF-Treated Samples by Kelvin Probe and Photoelectron Yield Spectroscopy.

Ambient-pressure Kelvin probe and photoelectron yield spectroscopy methods were employed to investigate the impact of the KF and RbF postdeposition treatments (KF-PDT, RbF-PDT) on the electronic features of Cu(In,Ga)Se (CIGSe) thin films and the CdS/CIGSe interface in a CdS thickness series that has been sequentially prepared during the chemical bath deposition (CBD) process depending on the deposition time. We observe distinct features correlated to the CBD-CdS growth stages. In particular, we find that after an initial CBD etching stage, the valence band maximum (VBM) of the CIGSe surface is significantly shifted (by 180-620 mV) toward the Fermi level.

Influence of Sulfur Evaporation during or after KF-Post Deposition Treatment On Cu(In,Ga)Se/CdS Interface Formation.

This work investigates the impact of the elemental sulfur evaporation during or after KF-post deposition treatment (KF-PDT) on the resulting Cu(In,Ga)Se/chemical bath deposited(CBD)-CdS interface. Chemical composition of the various interfaces were determined through Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger spectroscopy (XAES). Cu(In,Ga)Se absorber which experienced KF-PDT in selenium atmosphere (KSe sample) exhibits the formation of the well-reported In-Se based topping layer.

Photocathode functionalized with a molecular cobalt catalyst for selective carbon dioxide reduction in water.

Artificial photosynthesis is a vibrant field of research aiming at converting abundant, low energy molecules such as water, nitrogen or carbon dioxide into fuels or useful chemicals by means of solar energy input. Photo-electrochemical reduction of carbon dioxide is an appealing strategy, aiming at reducing the greenhouse gas into valuable products such as carbon monoxide at low or without bias voltage. Yet, in such configuration, there is no catalytic system able to produce carbon monoxide selectively in aqueous media with high activity, and using earth-abundant molecular catalyst.

Layered Quaternary Compounds in the CuS-InS-GaS system.

Several new materials with four structure-types (e.g., CuInGaS (CIGS), CuInGaS (CIGS), CuInGaS (CIGS), and CuInGaS (CIGS)) have been evidenced in the CuS-InS-GaS pseudo-ternary system.

Composition-Dependent Passivation Efficiency at the CdS/CuIn Ga Se Interface.

The bandgap of CuIn Ga Se (CIGS) chalcopyrite semiconductors can be tuned between ≈1.0 and ≈1.7 eV for Ga contents ranging between x = 0 and x = 1.

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for Cu(In,Ga)Se2 Solar Cells.

The levelized cost of electricity (LCOE) of photovoltaic (PV) systems is determined by, among other factors, the PV module reliability. Better prediction of degradation mechanisms and prevention of module field failure can consequently decrease investment risks as well as increase the electricity yield. An improved knowledge level can for these reasons significantly decrease the total costs of PV electricity.

Crystal Chemistry, Optical-Electronic Properties, and Electronic Structure of CdInS Compounds (0 ≤ x ≤ 1), Potential Buffer in CIGS-Based Thin-Film Solar Cells.

CdInS and InS compounds were both previously studied as buffer layers in CIGS-based thin-film solar cells, each of them exhibiting advantages and disadvantages. Thus, we naturally embarked on the study of the CdInS-InS system, and a series of CdInS (0 ≤ x ≤ 1) materials were prepared and characterized. Our results show that two solid solutions exist.

Finding Relevant Parameters for the Thin-film Photovoltaic Cells Production Process with the Application of Data Mining Methods.

A data mining approach is proposed as a useful tool for the control parameters analysis of the 3-stage CIGSe photovoltaic cell production process, in order to find variables that are the most relevant for cell electric parameters and efficiency. The analysed data set consists of stage duration times, heater power values as well as temperatures for the element sources and the substrate - there are 14 variables per sample in total. The most relevant variables of the process have been found based on the so-called random forest analysis with the application of the Boruta algorithm.

Effect of the KF post-deposition treatment on grain boundary properties in Cu(In, Ga)Se thin films.

Significant power conversion efficiency improvements have recently been achieved for thin-film solar cells based on a variety of polycrystalline absorbers, including perovskites, CdTe, and Cu(In,Ga)Se (CIGS). The passivation of grain boundaries (GBs) through (post-deposition) treatments is a crucial step for this success. For the case of CIGS, the introduction of a potassium fluoride post-deposition treatment (KF-PDT) has boosted their power conversion efficiency to the best performance of all polycrystalline solar cells.

Impact of Annealing-Induced Intermixing on the Electronic Level Alignment at the In2S3/Cu(In,Ga)Se2 Thin-Film Solar Cell Interface.

The interface between a nominal In2S3 buffer and a Cu(In,Ga)Se2 (CIGSe) thin-film solar cell absorber was investigated by direct and inverse photoemission to determine the interfacial electronic structure. On the basis of a previously reported heavy intermixing at the interface (S diffuses into the absorber; Cu diffuses into the buffer; and Na diffuses through it), we determine here the band alignment at the interface. The results suggest that the pronounced intermixing at the In2S3/CIGSe interface leads to a favorable electronic band alignment, necessary for high-efficiency solar cell devices.

The effect of immunoglobulin immunadsorptions on delayed xenograft rejection of human CD55 transgenic pig kidneys in baboons.

Delayed xenograft rejection (DXR) remains a major obstacle in discordant xenotransplantation. As strategies of complement inhibition and xenogeneic natural antibody (Ab) removal have been shown to give prolonged xenograft survival, we endeavored to determine whether combining these two strategies would lead to an additive effect in terms of graft survival. The study was initiated with two groups, A and B, where group A received normal kidneys and group B received hCD55 transgenic kidneys.

The effect of mitoxantrone on anti-pig immunization in baboons.

Besides virological and physiological concerns, the success of xenotransplantation (Xt) is still dependent on the prevention of delayed xenograft rejection (DXR). Although multifactorial, DXR is mainly due to xenonatural antibody (Ab) recognizing their xenogenic antigen (Ag) followed by complement activation. Despite the use of intensive treatments capable of inhibiting the humoral response, DXR can still not be avoided and always occurs within weeks following transplantation.

Interaction of anti-HLA antibodies with pig xenoantigens.

Background: Many patients with renal failure are condemned to long-term dialysis with little prospect of transplantation because they are highly sensitized with immunoglobulin G (IgG) directed against class I human leukocyte antigens (HLA) of virtually all donors. Xenotransplantation could represent an attractive solution providing their alloantibodies (alloAb) do not recognize porcine motifs. Hitherto there has been no in vivo demonstration of any cross-reactivity and the objective of this work was to investigate this problem using a technique of extracorporeal pig kidney perfusion as a model of clinical xenografting.

Characterization of a polyclonal anti-Galalpha1-3Gal antibody from chicken.

A polyclonal antibody was raised against the Galalpha1-3Gal carbohydrate epitope, which is expressed by all mammals (except man and the closest primate species) by immunizing hens with rabbit erythrocyte membranes. IgY was isolated from egg yolks, and affinity-purified on a Galalpha1-3Gal-Synsorb column. Two percent of the initial IgY fraction was recovered.