Search

Triple-negative breast cancer (TNBC) is associated with metabolic heterogeneity and poor prognosis with limited treatment options. New treatment paradigms for TNBC remains an unmet need. Thus, therapeutics that target metabolism are particularly attractive approaches. We previously designed organometallic Au(III) compounds capable of modulating mitochondrial respiration by ligand tuning with high anticancer potency in vitro and in vivo. Here, we show that an efficacious Au(III) dithiocarbamate (AuDTC) compound induce mitochondrial dysfunction and oxidative damage in cancer cells. Efficacy of AuDTC in TNBC mouse models harboring mitochondrial oxidative phosphorylation (OXPHOS) dependence and metabolic heterogeneity establishes its therapeutic potential following systemic delivery. This provides evidence that AuDTC is an effective modulator of mitochondrial respiration worthy of clinical development in the context of TNBC. Metabolic-targeting of triple-negative breast cancer by gold anticancer agent may provide efficacious therapy. [ABSTRACT FROM AUTHOR]

Abstract: This work studies the performance of commercially available Al pastes for the rear side contact formation with an industrially feasible process. The pastes are specifically designed for local Al-BSF/PERC (Passivated emitter and rear cell) cells. With this type of metallization, fill factors (FF) up to 80% are demonstrated, to our knowledge, the highest FF ever reported on fully screen printed PERC cells with industrial type emitter. Additionally, the use of an AlSi eutectic (12.7% Si) target for PVD sputtering is evaluated in comparison to a reference process using a pure Al target with the same kind of deposition technique. It was found that the thickness of the Al p+ BSF layer realized with the 12.7% Si containing Al target is systematically thicker than the reference due to a smaller metal Si interface. With this method, solar cells have been fabricated showing a potential efficiency above 20%, with standard Ag front screen printing on 60 Ω/□ emitter. [Copyright &y& Elsevier]

Abstract: In this work, we report on a self-aligned nickel silicide formation technique based on excimer laser annealing (ELA). We evaluate this process for the front contact formation of industrial PERC type solar cells on random pyramid textured Si surfaces where damage to surface texture, emitter passivation, or to the shallow junction should be avoided or minimized. PERC type solar cells obtained by POCl3 diffusion were processed on large area (12.5x12.5cm2) CZ-Si. Self-aligned litho-free Ni/Cu contacts defined by ps-laser ablation of the SiO2/SiNx anti-reflective coating (ARC) and subsequent ELA of the Ni layer were compared to conventional Ag screen printed contacts. The novel ELA process results in an absolute gain in Jsc of 0.8mA/cm2 as well as a drop of 0.3Ω.cm2 in series resistance (Rs) compared to SP Ag contacts due to reduced shading and resistance losses. This leads to 0.5% absolute increase in efficiency from 19.3% to 19.7% since other characteristics (Voc, pFF) could be maintained to the same level. In this work, the best performing cell with the ELA process reached an outstanding 20.0% energy conversion efficiency with Jsc=39.3mA/cm2, Voc=649.8mV, and FF=78.3%. [Copyright &y& Elsevier]

Abstract: In the future, thin (<100um) crystalline silicon (c-Si) solar cells based on amorphous heterostructures (a-Si:H/c-Si) are likely to become an essential branch of wafer-based photovoltaic industry. Within this thin technology, the surface passivation will have a larger influence on effective minority charge carrier lifetime, therefore an accurate analysis of the a-Si:H/c-Si interface is paramount to achieve high efficiencies. In this paper we studied an in-situ hydrogen (H2) plasma pretreatment before a-Si:H deposition, obtaining a surface recombination velocity (Srec) of 3.8±1.0cm/s at 1x1015 minority charge carriers/cm3 on moderately-doped n-type <100> silicon wafers and, therefore, we show a significant drop compared to the reference value (6.9±1.4cm/s). The trend is related to a change in surface hydrogen configuration toward lower hydrides (from SiH3 to SiH2 and SiH) and, thus, it indicates an atomic reconstruction more suited for the growth of a-Si:H(i) passivating layer. However, if the treatment is extended above an optimum time, the Srec increases abruptly above 10cm/s which suggests the introduction of defects. These effects are explained by hydrogen-induced reactions on the c-Si surface during the H2 pretreatment. The exposure to H2 plasma improves surface passivation without relevant modifications in the a-Si:H deposition process itself: hence, it represents an interesting option to be implemented in future heterojunction solar cells. [Copyright &y& Elsevier]

Abstract: Atomic layer deposition (ALD) of thin Al2O3 (≤ 10nm) films is used to improve both front and rear surface passivation of large-area screen-printed p-type CZ Si passivated emitter and rear cells (PERC). As emitter passivation, the SiNx anti reflection coating (ARC) is capped with Al2O3, giving improved hydrogenation during co-firing and a front recombination current (J0,front) of 128 ± 5 fA/cm2. As rear surface passivation, a blister-free stack of Al2O3/SiOx/SiNx is employed, leading to optimal back reflection and a rear recombination current (J0,rear) of 92 ± 6 fA/cm2. Internal quantum efficiency (IQE) measurements clearly confirm the improved passivation properties of both Al2O3-based stacks, even compared to passivation stacks based on thermally grown SiO2. [Copyright &y& Elsevier]

Abstract: This work focuses on using copper (Cu) as the main conductor as an alternative to standard screen printed silver (Ag) front contacts for homogeneous emitter silicon solar cells. Two different approaches to form Cu plated contacts based on laser ablation of the SiNx:H antireflection coating (ARC) and subsequent plating steps are presented. In the first approach, contacts are formed by Ni/Cu/Ag plating in an industrial in-line plating tool and subsequent rapid thermal annealing (RTA). In the second approach, the RTA step is performed after sputtering of a thin nickel layer and prior to the final Ni/Cu/Ag plating sequence. Using the latter approach, results are presented on large area 12.5×12.5 cm2 p-type CZ-Si PERC-type solar cells featuring an advanced 120Ω/sq homogeneous emitter and local Al contacts on the rear surface accompanied by a SiOx/SiNx rear side passivation stack. Solar cell efficiencies of up to η=19.6% and average pull tab adhesion results >2N are reported. [Copyright &y& Elsevier]

Abstract: This work focuses on the mechanisms of alkaline electroless Ni deposition on n-type Si substrates and silicide formation by rapid thermal treatment. The deposited Ni layers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy (EDS), and electron energy loss spectroscopy (EELS). The results indicate that Ni deposition occurs in two steps; a nucleation step, dominated by electrochemical processes, followed by autocatalytic deposition of Ni involving the reducing agent NaH2PO2. The oxygen content was found to be uniform in the Ni layer and was higher close to the Si/metal interface. The silicide formation from alkaline Ni deposits was characterized by 4 point probe measurements, in-situ x-ray dispersion (XRD) measurements, and TEM measurements. Results were compared to silicides formed from ‘pure’ sputtered Ni layers. It was observed that the silicide-formation temperature is higher for an electroless Ni layer than that for a sputtered Ni layer. The results suggest that the temperature ramping rate influences crystallographic phase formation. [Copyright &y& Elsevier]

Abstract: The PV industry has to systematically reduce its manufacturing cost in order to reach grid parity for the main markets in the coming decade. Crystalline Si solar cells are dominating presently the PV-market and this dominance is expected to continue for at least the next decade. Industrial production at a cost of 1$/Wp for crystalline Si solar cells has been announced for 2011. Increasing cell efficiencies is a prominent pathway in view of the strong leverage on costs of materials in the module fabrication sequence. In order to further reduce $/Wp costs, eventually down to the 0.5 $/Wp level, it is clear that the dominant position of crystalline Si solar cells on the market was partially achieved thanks to the existing knowledge and equipment base within the context of micro(nano)-electronics, although the cost drivers in both cases are principally different: cost/functionality reduction for microelectronics versus cost/Wp for photovoltaics. In order to achieve the ambitious goals stated higher, it makes sense to have a closer look how the process and analysis toolbox available in the microelectronics area can be used at the benefit of the further development of crystalline Si-based photovoltaic devices. The use of a nanotechnology toolbox is however not limited to crystalline Si solar cells. Also fields like concentrator PV (CPV) might take profit from developments in the domain of photonics enabled by the technological capabilities developed within micro(nano)electronics. The present paper gives an overview of a number of approaches being followed in IMEC to use the broad nanotechnology toolbox of microelectronics and microsystems for crystalline Si solar cells. [Copyright &y& Elsevier]

Abstract: Excellent front surface passivation is one of the key issues for interdigitated back contact (IBC) silicon solar cells. To create a better understanding of passivation properties and find the most important issues when developing passivation schemes for various injection conditions, an advanced simulation model is needed. The software package Sentaurus TCAD is applied in this work. The main input parameters of the model are the interface state density, the amount of fixed charges, the capture cross sections and the activation energies which have been determined experimentally as reported previously. As an example, simulation results of the advanced model of the recombination at the Si-SiNx interface were presented and compared to the measured data. [Copyright &y& Elsevier]

Amorphous AsxS100−x films were prepared by thermal evaporation and plasma-enhanced chemical vapour deposition (PECVD). Reversible photodarkening upon illumination with white light at 300 and 77 K was studied for both types of films. The magnitude of photodarkening increased with increasing As content, being somewhat larger for the evaporated films than for the PECVD ones. In agreement with our previous observations in the amorphous As–Se and Ge–Se systems, the shift of the optical absorption edge was not parallel but was always accompanied by a decrease in the slope of the Tauc curve, indicating an increase in disorder. The kinetics of the photoinduced optical shift could be best described by a stretched exponential law. This can be explained within Tanaka''s “single–double well model” with the addition that the process is most probably a kind of self-limiting process, whereby excitation to a quasi-stable state (photodarkening) and annealing (thermal and photoinduced) are simultaneously operative. [Copyright &y& Elsevier]