Impact of the ZnS layer position in a stacked precursor film on the properties of CZTS films grown on flexible molybdenum substrates
Küçük Resim Yok
Tarih
2023
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In the present study, CZTS thin films were prepared by annealing and reaction of Cu-Sn-ZnS precursor layers. First, sputter deposition was carried out on flexible molybdenum (Mo) foil to form Mo-foil/CuSn/ZnS/Cu, Mo-foil/CuSn/Cu/ZnS and Mo-foil/ZnS/CuSn/Cu stacked precursor structures. Annealing process was performed in sulfur atmosphere using Rapid Thermal Processing (RTP) method to obtain kesterite CZTS phase in the reacted layers. All prepared precursors and CZTS thin films displayed Cu-poor and Zn-rich chemical composition, as targeted. XRD patterns of CZTS samples showed that the kesterite phase was obtained in all samples regardless of the stacking order of the precursor films. However, the full width at half maximum (FWHM) values of the (112) preferential peaks extracted from the XRD patterns, and the corresponding structural parameters (crystallite size and microstrain), indicated that the Mo-foil/ZnS/CuSn/Cu precursor structure yielded more promising crystal-line quality. The occurrence of kesterite phase in all samples and existence of low amount of CTS phase were verified by Raman spectroscopy measurements. The CZTS sample prepared employing the Mo-foil/ZnS/CuSn/Cu precursor film structure presented more prominent, homogenous and compact surface microstructure as observed in SEM images. Optical band gap values were found to be in the range of 1.44-1.50 eV. The room temperature photoluminescence (PL) measurements showed that the transitions from the conduction band to intrinsic defect levels dominated the spectra instead of the band-to-band transitions. Electrical characterization of the films showed that Mo-foil/CuSn/ZnS/Cu and Mo-foil/ZnS/CuSn/Cu precursor films yielded lower elec-trical resistivity and higher carrier concentration due to better crystalline quality. Overall, it was seen that the CZTS thin films produced using the Mo-foil/ZnS/CuSn/Cu stacked precursor layers displayed better properties in terms of crystalline quality, surface microstructure, and optical and electrical properties, which are favorable for photovoltaic applications.
Açıklama
Anahtar Kelimeler
CZTS, Mo foil, Flexible substrate, Stacking order, RTP, Thin film solar cell
Kaynak
Optical Materials
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
136
