Far infrared spectroscopy and imaging of Cu(In,Ga)Se₂ layers

Abstract

The Fourier transform infrared spectroscopy (FT-IR), terahertz time domain spectroscopy (THz-TDS), and terahertz imaging were applied to study the properties of Cu(In, Ga)Se 2 (CIGS) layers grown on Mo/soda lime glass substrate. Correlation between the Infrared reflectivity spectrum around 5-7 THz (167-233 cm -1 ), Raman spectra, and X-ray diffraction data is investigated for samples grown on the molybdenum layer of approximately 1 μm in thickness. Also, transparency of CIGS layers was demonstrated for frequencies down to several hundred gigahertzes. Such transparency opens possibilities for future three-dimensional characterization of CIGS structures using phase sensitive imaging.