Fabrication of ternary Cu–Sn–S sulfides by a modified successive ionic layer adsorption and reaction (SILAR) method

Abstract

have been successfully synthesized by annealing three precursor film samples deposited via a modified successive ionic layer adsorption and reaction (SILAR) method. The mechanism of ion-exchange and improvement of the rinsing procedure were introduced into the SILAR process for the purpose of achieving the codeposition of different metal sulfides and increasing the growth rate of thin films. The crystal structure, composition, surface morphology, optical and electrical properties of three ternary sulfide samples have been characterized. The temperature dependence of the Seebeck coefficient, electrical conductivity, thermal conductivity and ZT values of the Cu 3 SnS 4 thin film sample have also been measured between 293 K and 573 K. Owing to the intrinsic advantages of the SILAR method and the improvement of the SILAR process, ternary Cu-Sn-S thin films can be deposited on glass substrates at a speed of 400 nm per hour and the surface morphologies of the thin films are comparable with those of thin films prepared by vacuum based methods, which can satisfy the requirements for high quality, high efficiency and low-cost production of thin films. With the appropriate band gap energies (1.0 eV, 1.45 eV and 1.47 eV for Cu 2 SnS 3 , Cu 5 Sn 2 S 7 and Cu 3 SnS 4 respectively) and considerable absorption coefficients (a > 10 4 cm À1 ), most importantly with earth-abundant elements, Cu-Sn-S thin films can be used as alternative absorber layer materials in thin film solar cells. Additionally for the Cu 5 Sn 2 S 7 and Cu 3 SnS 4 film samples, some novel properties (such as strong optical absorption in the NIR band, excellent conductivity and suitable carrier concentration) make them attractive for potential research interest as thermoelectric materials.

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

“…To better understand the band structure alterations, we have calculated the density of states (DOS) and formation energies (d H ) of Cu 6 Sn 2+y S 8 (y=0,1,2) and Cu 24-y Sn 8+y S 32 (y=0,1 Sn content increasing, although the calculated bandgap (E g ) (E g = ~1.25 eV) remains almost constant. The calculated E g values are lower than those reported (1.5~1.6 eV), 17 which might be due to the GGA problem. 30,31 However, the impurity levels gradually creates within the gap as y value increases, see the magnified pattern as an inset in panel B(c), and this level seems to merge with the conduction band with Sn content increasing.…”

“…[15][16][17] This compound is easy to be synthesized because it has a wide thermodynamic stability window due to a large chemical potential phase space. 18,19 …”

New materials for tunable plasmonic colloidal nanocrystals

“…For example, compounds like Cu 2 SnS 3 , Cu 5 Sn 2 S 7 and Cu 3 SnS 4 are all traditionally known as intrinsic semiconductors. However, recent work has shown NIR absorption from them that may be indicative of a LSPR, 154 and also metallic conductivity in some cases. 155 Whether this absorption/conductivity truly originates from them (for example due to mixed valence of the anion sublattice) and is not due to spurious Cu 2Àx S phases or even to d-d transitions related to Cu(II) species is something that needs to be carefully validated in the future.…”

Synthesis and Optical Characterization of Silver Nanoparticles (Ag-NPs) Thin Films (TFs) Prepared by Silar Technique

“…Among all of this methods, SILAR is the inexpensive, simplest, possible homogeneous deposition on large and complicated area of substrates, less temperature, easy to handle and low time consuming technique compared to the others (Salunkhe et al, 2009;Su et al, 2012;Mukherjee and Mitra, 2015). SILAR offers a great opportunity and a good numbers of advantages: SILAR does not require high quality target or substrates nor does it require vacuum at any stage, easily controlled rate of the film or nanoparticle deposition and the thickness by changing the deposition cycles, production of films or nanoparticle can be made possible at room temperature on less robust materials.…”