Title :
Na Incorporation in Cu(In,Ga)(Se,S)2 Films Grown on Insulator-Coated Stainless Steel Foil Using a Metal Precursor Reaction
Author :
Kihwan Kim ; Eser, Erten ; Shafarman, William N.
Author_Institution :
Inst. of Energy Conversion, Univ. of Delaware, Newark, DE, USA
Abstract :
Cu(In,Ga)(Se,S)2 (CIGSS) films are formed on flexible 430 stainless steel foils through reacting Cu-In-Ga metal precursors in H2 Se and H2S. The foils are coated using an electrically insulating silicone-based resin that can sustain temperatures as high as 600 °C. NaF films with various thicknesses are deposited between the metal precursor and Mo back contact in order to incorporate Na into the CIGSS films. The metal precursor reaction with the extrinsic Na incorporation results in greater Ga homogenization and S incorporation. The higher Na incorporation enhances VOC and lowers JSC . The temperature-dependent VOC and drive-level capacitance profiling measurements reveal that the Na incorporation results in higher activation energy of the recombination and increased carrier density.
Keywords :
capacitance; carrier density; copper compounds; gallium compounds; indium compounds; semiconductor thin films; sodium; ternary semiconductors; CIGSS films; Cu(InGa)(SeS)2:Na; Mo; Na incorporation; activation energy; carrier density; drive-level capacitance profiling; electrically insulating silicone-based resin; flexible 430 stainless steel foils; homogenization; insulator-coated stainless steel foil; metal precursor reaction; recombination; temperature-dependent VOC; Charge carrier density; Metals; Performance evaluation; Photonic band gap; Photovoltaic cells; Photovoltaic systems; Substrates; Flexible electronics; photovoltaic cells; semiconductor films; thin films;
Journal_Title :
Photovoltaics, IEEE Journal of
DOI :
10.1109/JPHOTOV.2015.2435366
