Effect of selenium content of CuInSe_x alloy nanopowder precursors on recrystallization of printed CuInSe₂ absorber layers during selenization heat treatment

E. Zaghi, Armin,Buffiè,re, Marie,Koo, Jaseok,Brammertz, Guy,Batuk, Maria,Verbist, Christophe,Hadermann, Joke,Kim, Woo Kyoung,Meuris, Marc,Poortmans, Jef,Vleugels, Jef Elsevier 2015 THIN SOLID FILMS - Vol.582 No.-

<P><B>Abstract</B></P> <P>Polycrystalline CuInSe<SUB>2</SUB> semiconductors are efficient light absorber materials for thin film solar cell technology, whereas printing is one of the promising low cost and non-vacuum approaches for the fabrication of thin film solar cells. The printed precursors are transformed into a dense polycrystalline CuInSe<SUB>2</SUB> semiconductor film via thermal treatment in ambient selenium atmosphere (selenization). In this study, the effect of the selenium content in high purity mechanically synthesized CuInSe<SUB>x</SUB> (x=2, 1.5, 1 or 0.5) alloy precursors on the recrystallization of the CuInSe<SUB>2</SUB> phase during the selenization process was investigated. The nanostructure and phase variation of CuInSe<SUB>x</SUB> nanopowders were investigated by different characterization techniques. The recrystallization process of the 1–2μm thick CuInSe<SUB>x</SUB> coatings into the CuInSe<SUB>2</SUB> phase during selenization in selenium vapor was investigated via in-situ high temperature X-ray diffraction. The CuInSe<SUB>x</SUB> precursors with lower selenium content showed a more pronounced phase conversion into CuInSe<SUB>2</SUB> compared to the higher selenium content CuInSe<SUB>x</SUB> precursors. Moreover, the CuInSe<SUB>x</SUB> (x=0.5 and 1) precursor resulted in a denser polycrystalline CuInSe<SUB>2</SUB> semiconductor film with larger crystals. This could be attributed to a more intensive atomic interdiffusion within the CuInSe<SUB>x</SUB> precursor system compared to a CuInSe<SUB>2</SUB> phase precursor, and the formation of intermediate CuSe and CuSe<SUB>2</SUB> fluxing phases during selenization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CuInSe<SUB>x</SUB> (x=2, 1.5, 1 or 0.5) alloy nanopowders were synthesized as CuInSe<SUB>2</SUB> precursor. </LI> <LI> Nanostructures of CuInSe<SUB>x</SUB> alloy nanopowders were investigated by HR-TEM. </LI> <LI> The CuInSe<SUB>x</SUB> conversions into the CuInSe<SUB>2</SUB> were studied by in-situ HT-XRD selenization. </LI> <LI> The CuInSe<SUB>2</SUB> precursor showed no significant grain growth during selenization. </LI> <LI> The CuInSe<SUB>0.5</SUB> precursor showed the most significant grain growth during selenization. </LI> </UL> </P>

CCM key comparison CCM.D-K4 'Hydrometer'

Lorefice, S,Becerra, L O,Lenard, E,Lee, Y J,Lee, W G,Madec, T,Meury, P A,Caceres, J,Santos, C,Vamossy, C,Man, J,Fen, K,Toda, K,Wright, J,Bettin, H,Toth, H BUREAU INTERNATIONAL DES POIDS ET MESURES 2016 METROLOGIA -BERLIN- Vol.53 No.-

<P></P> <P>This report presents the comparison philosophy, methodology, analysis and the results of the designed CCM.D-K4 key comparison that covered the calibration of high resolution hydrometers for liquid and alcoholometers in the density range 600 kg/m<SUP>3</SUP> to 2000 kg/m<SUP>3</SUP> at the temperature of 20°C. The main purpose of this comparison was not only to evaluate the degree of equivalence in the calibration of high accuracy hydrometers between NMI participants, but also to link, were it is possible, the results of previous comparisons to Key Comparison Reference Values (KCRVs) of CCM.D-K4. Eleven NMI laboratories took part in the CCM.D-K4 divided in two groups (petals).</P> <P>With the CCM.D-K4 purpose, two similar sets consisting of three hydrometers for liquid density determinations and an alcoholometer were circulated to the NMI participants as a travelling standard in the time interval from January 2011 to April 2012.</P> <P>Twelve Key Comparison Reference Values (KCRVs) for each petal have been obtained at the density values related to the tested density marks of the transfer standards by the results of participants. The KCRVs and corresponding uncertainties were calculated by the weighted mean in the case of consistent results, otherwise the median was used.</P> <P>The degree of equivalence (DoE) with respect to the corresponding KCRV was determined for each participant and, in this particular comparison, the Weighted Least Squares (WLS) method was used to link the individual DoE of each participant by a continuous function.</P> <P>Significant drift of the transfer standards was not detected.</P> <P>This report also gives instructions on calculating pair-wise degrees of equivalence, with the addition of any information on correlations that may be necessary to estimate more accurately as well as the procedure for linking international comparisons to the CCM.D-K4. Finally an example of linkage to the CCM.D-K4 is given by dealing with the results of the bilateral comparison between INRiM and NMIA, which was added to this comparison so that all participants were engaged after the breakage of the 9340171 artefact.</P> <P>A particularly good agreement was found among the results provided by most of the participants, even if some systematic differences and either underestimated or overestimated uncertainties of the submitted results can be identified with respect to the KCRVs. In general the deviations of the laboratory results to the KCRVs are within of 1/3rd to 1/4th of a scale division and the uncertainty at 95% is usually within half a division. During the analysis of the submitted results, a systematic difference between the first and last immersed mark was also noted, possibly due to a temperature gradient along the stem and/or wetting of the stem around the tested mark, and therefore a corrected claimed uncertainty from each laboratory is expected. However this comparison may help the laboratories to solve some residual or marginal problems as well as to better understand the uncertainty components.</P> <P>The comparison fully supports the calibration measurement capabilities table in the BIPM key comparison database (KCDB). The results can be used to link regional comparisons to this CCM key comparison</P> <H2>Main text</H2> <P> To reach the main text of this paper, click on <A HREF='http://www.bipm.org/utils/common/pdf/final_reports/M/D-K4/CCM.D-K4_Final_Report.pdf'>Final Report</A>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <A HREF='http://kcdb.bipm.org/'>kcdb.bipm.org/</A>.</P> <P>The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

Final report on CCM.M-K4: Key comparison of 1 kg stainless steel mass standards

Becerra, Luis Omar,orys, Michael,Chung, Jin Wan,Davidson, Stuart,Fuchs, Peter,Jacques, Claude,Jian, Wang,Kubarych, Zeina J,Kumar, Anil,Malengo, Andrea,Fen, Kitty,Medina, Nieves,Meury, Paul-André BUREAU INTERNATIONAL DES POIDS ET MESURES 2014 METROLOGIA -BERLIN- Vol.51 No.-

<P>This report describes a key comparison of 1 kg stainless steel mass standards, CCM.M-K4, undertaken by the Consultative Committee for Mass and Related Quantities (CCM) Working Group on the Dissemination of the kilogram (WGD-kg). The CCM.M-K4 comparison was launched during the 12th meeting of the CCM (2010). The aim of the present comparison is to verify the consistency of 1 kg stainless steel mass standards among members of the CCM.</P><P>The previous CCM 1 kg stainless steel mass standards comparison was carried out in 1995–1997 as the CCM.M-K1 comparison. The Bureau International des Poids et Mesures (BIPM) was the pilot laboratory for this key comparison. There were sixteen participants in the CCM.M-K4 comparison, all are CCM members. The comparison was structured into four petals with two stainless steel travelling mass standards per petal. The measurements and the reported results were completed in between one month and five months depending on the participants. One laboratory's results were found to be inconsistent with the other laboratories' results and one other laboratory gave a significant deviation from the key comparison reference value (KCRV). Both laboratories were contacted before preparation of the draft A report, without disclosing the details of the deviations, to allow them to check and revise their values. The fourteen other participants were in agreement with each other and degrees of equivalence have been established.</P><P>Finally, the mass values of the eight stainless steel travelling standards were determined in air by the NMIs with claimed standard uncertainties ranging from 0.007 mg to 0.021 mg. Degrees of equivalence have been established by using the generalized linear least-squares estimation (GLS) method. The result demonstrates the high quality of this comparison and that some participants are able to provide, for their mass calibration services, standard uncertainties of around ten micrograms. The good uniformity of worldwide mass dissemination since the last periodic mass verification carried out in 1992 is demonstrated by the agreement among the NMIs' results. In addition, the observed weighted mean of the NMI deviations against the BIPM is −0.0098 mg (σ = 0.0036 mg). Despite the good result obtained in this particular comparison we should, in order to have a more accurate calibration system, improve the knowledge of the ageing effects of the mass references and increase the BIPM calibration frequency of the national prototypes.</P><P>Main text.To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.</P><P>The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>