Molybdenum incorporated Cu1.69ZnSnS4 kesterite photovoltaic devices with bilayer microstructure and tunable optical-electronic properties

摘要: Abstract Molybdenum (Mo) incorporated Cu1.69ZnSnS4 (CZTS) absorber has been deposited onto Mo-coated soda lime glass (SLG) by co-sputtering of Mo and non-stoichiometric quaternary compound targets. After sulfurization at 600 °C, incorporation into CZTS was confirmed X-ray diffraction (XRD) secondary ion mass spectrometry (SIMS). From the observed shifts for (1 1 2) (2 2 0) peaks, both lattice parameters a c unit cell were found to decrease with increasing suggesting cationic substitution Mo. The bilayer microstructure in which lower sub-layer adjacent substrate smaller grain size higher porosity than upper sub-layer. is also richer graded profile. Sheet resistance measurements on films SLG quartz show resistivity that decreases amount acts as an acceptor dopant. energy band gap increases from 1.38 eV about 1.68 eV result absorbance increased wavelengths shorter 600 nm. When co-deposited optimized DC sputtering power 10 W, CZTS/CdS solar cells attain maximum conversion efficiency (PCE) 5.49% versus 1.63% reference device under 1 Sun AM 1.5 illumination. Device enhancement due back surface field, carrier concentration reduced tailing.