Optical phonons in pentanary compound (Ag Cu1−)2ZnSnS4 semiconductor: A raman study

Spectroscopy and Theoretical Modeling of Phonon Vibration Modes and Band Gap Energy of Cu2ZnSn(SxSe1–x)4Bulk Crystals and Thin Films

“…The only difference is a much lower content of Zn (5.3%) and a higher Cu (37.3%) content compared to those reported by Wang et al It should be noted that the Sn content (15%) is higher than the recommended one (12.5%) for pure CZTS and CZTSe compounds . Obviously, a lack of Zn together with an excessive amount of Cu and Sn leads to the formation of a pair of antisite defects, Zn Cu + + Cu Zn – and Sn Zn + + Zn Sn – . ,, The formation of defect pairs, namely, the substitution of Zn with Cu and Sn atoms in the CZTSSe crystal lattice, may be responsible for the realization of pyramid-like structures due to their similar ionic radii (Sn0.69 Å, Cu0.74 Å, and Zn0.74 Å) . The elemental analysis in Figure S1c and Table S1 shows that the increase in Se content to 27.4% results in a decrease in the S content to 15%.…”

“…34,48,49 The formation of defect pairs, namely, the substitution of Zn with Cu and Sn atoms in the CZTSSe crystal lattice, may be responsible for the realization of pyramid-like structures due to their similar ionic radii (Sn 0.69 Å, Cu0.74 Å, and Zn0.74 Å). 35 The elemental analysis in Figure S1c and Table S1 shows that the increase in Se content to 27.4% results in a decrease in the S content to 15%. This corresponds to the expected result at the specified ratio of these elements [x = 15.0/(15.0 + 27.4) = 0.35].…”

“…In the Raman spectra of multicomponent crystals, the full width at half-maximum (FWHM) of main peaks and the intensity of shoulder peaks depend on the disorder of cations . It is also worth remembering that the formation of pairs of antisite defects Cu Zn and Zn Cu is one of the most common methods in these compounds (it reduces E g , when forming donor–acceptor pairs Zn Cu + + Cu Zn – ). − These defect complexes can act as recombination centers for the charge carriers, thereby limiting the open-circuit voltage ( V oc ) and, hence, the efficiency of CZTSSe-based photovoltaic devices . This is why, along with the ever-rising number of experimental publications in this area, the number of theoretical studies is also growing. ,− …”

“…32−34 These defect complexes can act as recombination centers for the charge carriers, thereby limiting the open-circuit voltage (V oc ) and, hence, the efficiency of CZTSSe-based photovoltaic devices. 35 This is why, along with the ever-rising number of experimental publications in this area, the number of theoretical studies is also growing. 34,36−40 The aim of the present study is to identify patterns between the elemental composition, crystal structure, and band gap, being important for creating TFSCs with an enhanced efficiency.…”

Raman and X-ray Photoelectron Spectroscopic Study of Aqueous Thiol-Capped Ag-Zn-Sn-S Nanocrystals

“…Most of the Raman studies of CAZTS and AZTS were performed on poly-/microcrystalline films [34][35][36][37][38][39], with only a few reports on colloidal NCs [9,11,40]. There is a noticeable discrepancy in the literature regarding the dependence of the phonon Raman peak position and width on the Ag content in CAZTS, the NC size, or non-stoichiometry [5,39].…”