Dielectric function and double absorption onset of monoclinic Cu 2 SnS 3 : Origin of experimental features explained by first-principles calculations

Abstract

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Silver-Doped Cu2SnS3Absorber Layers for Solar Cells Application

“…This is also reflected in the performance of CTS solar cells, since the highest efficiencies are obtained from the monoclinic phase [1], [3]- [5] and consistent band gap values of (0.93 ± 0.02) eV with another optical transition at 1.00 ± 0.03 eV [1]- [5] are reported. The visible second transition is due to the splitting of the valence band and confirms the monoclinic polymorph [13], [14], but does not exclude the simultaneous presence of the cubic polymorph. Another potential problem with CTS is that the net doping is too high for good current extraction [11], [15].…”

High absorption coefficients of the CuSb(Se,Te)2 and CuBi(S,Se)2 alloys enable high-efficient 100 nm thin-film photovoltaics

“…All DFTbased calculations were performed with HSE06 and with a cut-off energy of 420 eV. A large k-mesh can be important to describe details in the absorption coefficient [21,22]. However, from test calculations we have found that the effect is not crucial for the considered materials, and we use HSE06 (which avoids incorrect resonance across the underestimated gaps for local potentials [23,24]) and with the same k-mesh as for the calculations of the LDOS.…”

Enhancing the thermoelectric performance of Cu3SnS4-based solid solutions through coordination of the Seebeck coefficient and carrier concentration

“…The main drawback of restricting the applications of Cu-Sn-S compounds in thermoelectrics is their low electrical conductivities (σ) likely due to their wide bandgap (0.93-1.35 eV for Cu 2 SnS 3 , 6,7 1.0~1.80 eV for Cu 3 SnS 4 15-17 and 0.8 eV for Cu 4 Sn 7 S 16 3 ), and inharmonious relation of the Seebeck coefficient (α) and carrier concentration (n H ). Hence it is challenging to significantly improve their TE performance, which is described by the dimensionless figure of merit (ZT), ZT=Tα 2 σ / κ = Tα 2 σ / (κ e +κ L ).…”