Cu(In,Ga)Se2 (CIGSe) layers have been deposited by the 3-stage process and once the growth was completed, the structures have been kept at high temperature for 50min with or without Se supply. Both ...the resulting CIGSe layer and related device properties are compared with those obtained when the substrate is cooled down right after the deposition. Moreover, such experiments have been performed with and without alkali availability. The results show that keeping the absorber at high temperature differently impacts Ga/(In+Ga) atomic ratio distribution and crystalline preferential orientation depending on whether Se is supplied. Moreover, this work shows that chalcogen supply can be detrimental for cell performance when the CIGSe contains alkali and in contrast be beneficial when the CIGSe is free of alkali. These observations suggest an intimate relationship between alkali and Se.
•Annealing under Se flux appears detrimental if the absorber layer contains alkali.•The detrimental impact is due to increased interface recombination.•The same post-deposition treatment is beneficial if the absorber is alkali-free.•Alkali-free performance is improved thanks to increased net acceptor density.
Chimeric antigen receptors (CARs) are synthetic receptors that redirect and reprogram T cells to mediate tumor rejection. CD19 targeted CAR T cells have showed remarkable effacy for ...chemorefractory/relapsed B cell malignancies. Recombinant retroviral vectors mediated- CAR gene transfer is currently the standard method to generate cGMP grade CAR T cells. However, CAR gene expression is highly variable, owing to position effects and vector incorporation variations. CAR T cells engineered in this manner are capable of tumor eradication, but are prone to tonic signaling and accelerated exhaustion. We have developed a novel genetic engineering strategy to insert CAR genes into a precise genomic location in human peripheral blood T cells.
T cells are electroporated with Cas9 mRNA or Cas9 protein and a guide RNA, followed by transduction with a recombinant Adeno-Associated Virus encoding the CAR sequence to facilitate the insertion of the CAR gene upstream of the constant region of TCR alpha chain. This results in the endogenous TCR promoter (TRAC) controlled CAR expression and abrogation of TCR surface expression. This strategy not only allows uniform CAR expression, but also delays T-cell differentiation and exhaustion, leading to enhanced T cell function and anti-tumor efficacy. The edited cells vastly outperformes retrovirally modified CAR T cells in a pre-B ALL NALM6 mouse model. The targeting of CARs to the TCR locus also provides a safer therapeutic T cell by minimizing the risks of insertional oncogenesis, and TCR-induced autoimmunity and alloreactivity (thus spanning both autologous and allogeneic T cell applications). In addition, we have incorporated in the CAR a mutant CD3z chain encoding a single immunoreceptor tyrosine-based activation motif that improves the balance between effector and memory T cells composition.
We are in the process of translating this novel approach into the clinical setting by establishing cGMP conditions and protocols for the manufacturing of TRAC-CAR T cells. Using the 4D-LV electroporator, we have demonstrated that we can knockout the TCR at large scale (100 E06 CD3+ T cells) with high efficiency (70-80%) as that obtained at small scale. We have evaluated AAV6 to deliver the CAR transgene in the TCR locus. Data will be presented on optimizing the manufacturing of the TRAC-CAR T cells and on evaluating their anti-tumor efficacy in vivo.
The RD48 (ROSE) collaboration has succeeded to develop radiation hard silicon detectors, capable to withstand the harsh hadron fluences in the tracking areas of LHC experiments. In order to reach ...this objective, a defect engineering technique was employed resulting in the development of Oxygen enriched FZ silicon (DOFZ), ensuring the necessary O-enrichment of about 2×10
17 O/cm
3 in the normal detector processing. Systematic investigations have been carried out on various standard and oxygenated silicon diodes with neutron, proton and pion irradiation up to a fluence of 5×10
14
cm
−2 (1
MeV neutron equivalent). Major focus is on the changes of the effective doping concentration (depletion voltage). Other aspects (reverse current, charge collection) are covered too and the appreciable benefits obtained with DOFZ silicon in radiation tolerance for charged hadrons are outlined. The results are reliably described by the “Hamburg model”: its application to LHC experimental conditions is shown, demonstrating the superiority of the defect engineered silicon. Microscopic aspects of damage effects are also discussed, including differences due to charged and neutral hadron irradiation.
Results of high frequency modulated photocurrent spectroscopy (HF MPC) performed on epitaxial and polycrystalline CuGaSe2 thin films are presented. Frequency and temperature scans of MPC in the high ...frequency regime are compared, and the advantages of the second mode of measurement over the first one are demonstrated. Electronic parameters of defect levels in Cu-rich and Ga-rich stoichiometry are obtained and discussed in comparison to the literature data on defect levels derived from capacitance junction techniques. An attempt to correlate levels observed by MPC technique with material stoichiometry has been made.
Results of high frequency modulated photocurrent spectroscopy (HF MPC) performed on epitaxial and polycrystalline CuGaSe
2 thin films are presented. Frequency and temperature scans of MPC in the high ...frequency regime are compared, and the advantages of the second mode of measurement over the first one are demonstrated. Electronic parameters of defect levels in Cu-rich and Ga-rich stoichiometry are obtained and discussed in comparison to the literature data on defect levels derived from capacitance junction techniques. An attempt to correlate levels observed by MPC technique with material stoichiometry has been made.
This report summarises the final results obtained by the RD48 collaboration. The emphasis is on the more practical aspects directly relevant for LHC applications. The report is based on the ...comprehensive survey given in the 1999 status report (RD48 3rd Status Report, CERN/LHCC 2000-009, December 1999), a recent conference report (Lindström et al. (RD48), and some latest experimental results. Additional data have been reported in the last ROSE workshop (5th ROSE workshop, CERN, CERN/LEB 2000-005). A compilation of all RD48 internal reports and a full publication list can be found on the RD48 homepage (http://cern.ch/RD48/). The success of the oxygen enrichment of FZ-silicon as a highly powerful defect engineering technique and its optimisation with various commercial manufacturers are reported. The focus is on the changes of the effective doping concentration (depletion voltage). The RD48 model for the dependence of radiation effects on fluence, temperature and operational time is verified; projections to operational scenarios for main LHC experiments demonstrate vital benefits. Progress in the microscopic understanding of damage effects as well as the application of defect kinetics models and device modelling for the prediction of the macroscopic behaviour has also been achieved but will not be covered in detail.
