Antimony Sulfide Absorbers in Solar Cells

摘要

Abundance of antimony in the earth's upper crust is near 0.2 ppm, with an annual production nearly two hundred thousand tons, and 99.65% ingot price below US$15/kg, thus making antimony-based semiconductor compounds attractive for solar cells. The optical band gap (E_g) 1.5-1.8 eV of antimony sulfide qualifies it as a solar cell absorber, particularly in view of the solid solutions Sb_2Se_(3-x)Se with E_g 1-1.8 eV. We report here chemical deposition Sb_2S_3 of 300 nm in thickness using two methods. When used in CdS/Sb_2S_3/C-Ag cells prepared by either method, V_(oc) is up to 640 mV and J_(sc), 2-5 mA/cm~2 and efficiency, η is 0.5-1% under 1000 W/m~2 AM 1.5 G sunlight. Under concentrated sunlight, J_(sc) increases proportionately and V_(oc) logarithmically. Addition of a 400 nm of PbS thin film: CdS/Sb_2S_3/PbS/C-Ag improves V_(oc), but cell efficiency is 1%.