Structural, Optical and Electrical Conductivity Properties of Stannite Cu2ZnSnS4

Abstract

A precursor powder was obtained from drying the solutions of a mixture of different ratios of Cu, Zn and Sn chloride and thiourea. The Cu 2 ZnSnS 4 (CZTS) samples were prepared from thermal decomposition of the corresponding precursors in vacuum, and were then characterized using scanning emission microscopy, energy dispersive x-ray analysis, x-ray powder diffraction and Raman scattering. According to x-ray diffraction analysis, all the synthesized samples had a tetragonal structure of space group I42m. The electrical properties of the CZTS samples were investigated in the temperature range of 10-325 K. The charge carrier concentration was measured to be about p = 1 9 10 16 cm À3. A crossover from a nearest-neighbor hopping conduction mechanism at high temperatures (T > 150 K) to a Mott variable-range hopping conduction mechanism at low temperatures (T < 150 K) was observed. The activation energies of the CZTS samples were calculated for the low and high ranges of temperature. A thin film on quartz substrates was obtained using magnetron sputtering, for which a band gap of E g = 1.3 eV was determined from transmittance measurements.

Novel heterojunction superstrate Cu2ZnInS4−x (CZIS) thin film kesterite solar cell with vertical arrays of hexagonal ZnO nanorods window layer

“…The lattice parameters a were calculated to be 5.487, 5.540 and 5.484 Å at 150, 250 and 350 °C while the c values were estimated to be 11.090, 10.598 and 10.911 Å respectively. The obtained values agree well with what has been found in the literature for kesterite CZTS crystal structure [37][38][39].…”

“…The higher the temperature the more tetragonal structure CZIS assume. These values agree well with what has been reported for tetragonal CZTS crystal structure in the literature [37][38][39]. The number of dislocations in a unit volume of a crystalline material (dislocation density) is calculated from the Williamson and Smallman's relation [11,35].…”

Structural properties and variable-range hopping conductivity of Cu2SnS3

“…In the high-temperature region, the conductivity is governed by the NNH model, whereas in the low-temperature range, the conductivity of the samples is described by the Mott VRH conduction mechanism. This crossover from the NNH to the Mott VRH conduction mechanism was also observed in Cu 2 ZnSnS 4 material with tetragonal structure [25,26]. The transition from the NNH to the Mott VRH conduction is often stimulated by increasing the disorder in crystalline structures or lowering the temperature, since this condition is energetically advantageous for the making jumps with end points outside the closest center [22].…”