Statistical Analysis of Electroplated Indium (Ⅲ) Sulfide (In-2S_3) Films, a Potential Buffer Material for PV (Heterojunction Solar Cells) Systems, using Organic Electrolytes

摘要

In_2S_3 has received attention as an alternative to CdS as the buffer layer in heterojunction solar cells. Although having a bandgap of 2.0 eV relative to 2.5 eV for CdS, the lower toxicity and environmental impact of indium relative to cadmium, and significant photosensitivity, compel ongoing research.Indium sulfide thin films were deposited onto molybdenum-coated glass (SiO_2) substrates by electrodeposition from organic baths (ethylene glycol-based) containing indium chloride (InCl_3), sodium chloride (NaCl), and sodium thiosulfate (Na_2S_2O_3.5H_2O), the latter used as an additional sulfur source along with elemental sulfur (S). The Taguchi method was used to optimize the deposition paramters so as to minimize non-uniformity, cracks, and improper stoichiometry. The measured performance characteristics (molar ratio (In:S) and crack density) for all of the In_2S_3 films were calculated to analyze the effect of each deposition factor (deposition voltage, deposition temperature, composition of solution, and deposition time) involved in the electrodeposition process by calculating the sensitivity (signal to noise, S/N, ratios).