Ag–Cu–In–Ga Metal Precursor Thin Films for (Ag,Cu)(In,Ga)Se2 Solar Cells

The Ag-Cu-In-Ga (ACIG) material system has been investigated over a composition range used for reaction to form (Ag,Cu)(In,Ga)Se2 thin films for photovoltaic application. ACIG thin films were sputter deposited from Ag 0.77Ga0.23, Cu0.77Ga0.23, and In targets using different layer sequences with Ag/(Cu + Ag) and (Ag + Cu)/(Ga + In) ratios fixed at 0.25 and 0.90, respectively. The most uniform morphology was achieved with a Ag-Ga layer followed by a layer with co-sputtered Cu-Ga and In. Varying the sputtering sequence for stacked layers resulted in dissimilar morphologies and structural phases. X-ray diffraction analyses revealed that Ag-Ga and In layers intermix to form the (Ag,Cu)In2 phase in all Ag-containing samples except one with a Ag-Ga/Cu-Ga/In sequence. In addition, precursors were shown to be unstable during storage at room temperature, where a secondary (Ag,Cu*)In2 phase with higher Cu content formed. Finally, phase composition of the precursors annealed at 300°C was characterized.

[1]  C. Campbell,et al.  Cu–Ga–In thermodynamics: experimental study, modeling, and implications for photovoltaics , 2016, Journal of Materials Science.

[2]  Jinwoo Lee,et al.  Bandgap gradients in (Ag,Cu)(In,Ga)Se2 thin film solar cells deposited by three-stage co-evaporation , 2015, 2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC).

[3]  W. Shafarman,et al.  Structural and optical properties of (Ag,Cu)(In,Ga)Se2 polycrystalline thin film alloys , 2014 .

[4]  Kihwan Kim,et al.  Effect of sputtering sequence on the properties of Ag-Cu-In-Ga metal precursors and reacted (Ag,Cu)(In,Ga)Se2 films , 2014, 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC).

[5]  Jinwoo Lee,et al.  Characterization of group I-rich growth during (Ag,Cu)(In,Ga)Se2 three-stage co-evaporation , 2014, 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC).

[6]  S. Sommadossi,et al.  Phase Identification of Cu-In Alloys with 45 and 41.25 at.% In Compositions , 2014 .

[7]  S. Sommadossi,et al.  Crystallographic characterization of Cu–In alloys in the 30–37 at% In region , 2013 .

[8]  Kihwan Kim,et al.  Characterization of (AgCu)(InGa)Se$_{\bf 2}$ Absorber Layer Fabricated by a Selenization Process from Metal Precursor , 2013, IEEE Journal of Photovoltaics.

[9]  Kihwan Kim,et al.  Effect of Rapid Thermal Processing on the structural and device properties of (Ag,Cu)(In,Ga)Se2 thin film solar cells , 2013 .

[10]  J. Jung,et al.  Prediction of the Cu–Ga–In Ternary Phase Diagram , 2012 .

[11]  W. Shafarman,et al.  An Investigation of the Surface Properties of (Ag,Cu)(In,Ga)Se $_{\bf 2}$ Thin Films , 2012, IEEE Journal of Photovoltaics.

[12]  Antao Chen,et al.  Low Homologous Temperature (0.2) Sputtering of Indium Films on Silicon (POSTPRINT) , 2012 .

[13]  Kihwan Kim,et al.  Three-step H2Se/Ar/H2S reaction of Cu-In-Ga precursors for controlled composition and adhesion of Cu(In,Ga)(Se,S)2 thin films , 2012 .

[14]  W. Shafarman,et al.  Structural characterization of the (AgCu)(InGa)Se2 thin film alloy system for solar cells , 2011 .

[15]  C. Jeon,et al.  Effect of precursor structure on Cu(InGa)Se2 formation by reactive annealing , 2011 .

[16]  Jinwoo Lee,et al.  The electronic structure of Cu(In 1 - x Ga x)Se 2 alloyed with silver , 2011 .

[17]  G. Teeter,et al.  Wide-bandgap (AgCu)(InGa)Se2 absorber layers deposited by three-stage co-evaporation , 2010, 2010 35th IEEE Photovoltaic Specialists Conference.

[18]  C. Thompson,et al.  Device characterization of (AgCu)(InGa)Se2 solar cells , 2010, 2010 35th IEEE Photovoltaic Specialists Conference.

[19]  J. Dugué,et al.  Experimental Study of the Ternary Ag—Cu—In Phase Diagram , 2009 .

[20]  A. Takeuchi,et al.  Phase stability of Cu2Mg and CuMg2 compounds against noncrystallizations analyzed with a plastic crystal model , 2008 .

[21]  W. Shafarman,et al.  Incongruent reaction of Cu–(InGa) intermetallic precursors in H2Se and H2S , 2007 .

[22]  Jung-Hyun Park.  Microstructure Development and Evolution of Sputter Deposited Indium Thin Films in Cryogenics , 2007 .

[23]  Yinguo Xiao,et al.  Subsolidus Phase Relations of the Cu—Ga—N System. , 2007 .

[24]  P. Berwian,et al.  Phase relations in the ternary Cu–Ga–In system , 2007 .

[25]  Yinguo Xiao,et al.  Phase Relations of the Ag—Ga—N System. , 2007 .

[26]  R. Scheer,et al.  Real-time studies of phase transformations in Cu-In-Se-S thin films. 1. Intermetallic phase transformations , 2006 .

[27]  A. Weber,et al.  In situ investigation of the formation of Cu(In,Ga)Se2 from selenised metallic precursors by X-ray diffraction—The impact of Gallium, Sodium and Selenium excess , 2005 .

[28]  P. Berwian,et al.  Formation of CuInSe2 by the annealing of stacked elemental layers—analysis by in situ high-energy powder diffraction , 2003 .

[29]  R. Birkmire,et al.  Copper-indium alloy transformations , 2000 .

[30]  A. Olsen,et al.  Phase relations and crystal structures in the Ag–Ga system , 2000 .

[31]  H. Metzner,et al.  Coevaporated Cu–In films as precursors for solar cells , 1999 .

[32]  L. Stenberg,et al.  The ?-Phase Field of the Cu-In System. , 1998 .

[33]  L. Stenberg,et al.  The η-phase field of the CuIn system , 1997 .

[34]  R. Birkmire,et al.  Chemical reaction analysis of copper indium selenization , 1996 .

[35]  A. Larsson,et al.  A Survey of Superstructures in Intermetallic NiAs-Ni2In-Type Phases , 1995 .

[36]  A. D. Romig,et al.  Phase equilibria of the cu-in system I: Experimental investigation , 1993 .

[37]  M. Ellner,et al.  Powder Crystal Data for the High-Temperature Phases Cu4In, Cu9In4(h) and Cu2In(h) , 1992, Powder Diffraction.

[38]  J. Voigt,et al.  Studies of compound formation at CuIn, AgIn and AuIn interfaces with perturbed γ-γ angular correlations , 1986 .

[39]  W. A. Dollase,et al.  Correction of intensities for preferred orientation in powder diffractometry: application of the March model , 1986 .

[40]  Chris R. M. Grovenor,et al.  The development of grain structure during growth of metallic films , 1984 .

[41]  J. Thornton.  High Rate Thick Film Growth , 1977 .

[42]  J. L. Queisser,et al.  Ternary Chalcopyrite Semiconductors: Growth, Electronic Properties, and Applications , 1976 .

[43]  M. El-Boragy,et al.  Kristallstruktur von CuGa2 , 1972 .

[44]  F. Weibke,et al.  Das Zustandsdiagramm des Systems Silber–Indium , 1934 .

[45]  C. Muzzillo.  Chalcopyrites for solar cells: Chemical vapor deposition, selenization, and alloying , 2015 .

[46]  M. Aindow.  Preface to the 50th anniversary issue of the Journal of Materials Science , 2015, Journal of Materials Science.

[47]  Jinwoo Lee,et al.  The Comparison of (Ag,Cu)(In,Ga)Se$_{\bf 2}$ and Cu(In,Ga)Se$_{\bf 2}$ Thin Films Deposited by Three-Stage Coevaporation , 2014, IEEE Journal of Photovoltaics.

[48]  Kihwan Kim,et al.  Characterization of (AgCu)(InGa)Se2 absorber layer fabricated by a selenization process from metal precursor , 2013, 2012 IEEE 38th Photovoltaic Specialists Conference (PVSC) PART 2.

[49]  H. Dittrich,et al.  Ternary compounds, organic semiconductors , 2000 .