Annealing studies and electrical properties of SnS-based solar cells

Abstract

Thin films of SnS (tin sulphide) were thermally evaporated onto glass and CdS/ITO (cadmium sulphide/indium tin oxide) coated glass substrates and then annealed in vacuum with the aim of optimising them for use in photovoltaic solar cell device structures. The chemical and physical properties of the layers were determined using scanning electron microscopy, energy dispersive x-ray analysis, x-ray diffraction, and transmittance versus wavelength measurements. "Superstrate configuration" devices were also made using indium tin oxide as the transparent conductive oxide, thermally evaporated cadmium sulphide as the buffer layer and evaporated copper/indium as the back contact material. Capacitance-voltage data are given for the fabricated devices. Capacitancevoltage, spectral response and I-V data are given for the fabricated devices.

Physical properties of chalcogenide Sn–Bi–S graded thin films annealed in argon

“…Annealing can be seen to cause a change in crystallographic orientation with the sample annealed at 500°C that became more crystalline. Figure 4 shows that in this sample the intensity of main reflection for the SnS (130) plane at 31.6°increases with the annealing temperature, and the film exhibited stronger preferred orientation and became more crystalline, which is in agreement with previous studies [13], as a result of the removal of residual stresses/microstrain formed during deposition of the films, as shown in Fig. 5 and presented in Table 3, a similar observation has been made by other workers [21].…”

“…Tin sulfide (SnS) and bismuth sulfide (Bi 2 S 3 ) are candidate materials for sustainable photovoltaic applications with band gaps of *1.3 and *1.7 eV, respectively, that bracket the ideal value of 1.5 eV. Their band gaps are also direct, resulting in high optical absorption coefficients [12][13][14], indicating that future devices would only require a thin active layer to effectively absorb all incident light. We have studied earlier annealing effects on the microstructural properties of complex sulfosalt (SnS) x -(Bi 2 S 3 ) 1-x gradient thin films [15].…”

Grain size and lattice parameter's influence on band gap of SnS thin nano-crystalline films

“…Tin Sulfide (SnS), a IV-VI group semiconductor having orthorhombic double layered structure with weak Van der Waals bonds between the layers, is considered a potential candidate due to its properties like high absorption coefficient (∼ 10 4 cm −1 ) and band gap (of the order of ∼ 1.1 − 1.6 eV) [1,2]. SnS films are amphoteric in nature, i.e., they can exist either as 'n'-type or 'p'-type depending on the fabrication conditions [3,4]. SnS properties are also anisotropic [5,6,7] which along with its amphoterism demands an extensive investigation into its properties.…”

Band alignment of SnS/Zn(O,S) heterojunctions in SnS thin film solar cells

“…). 1 There have been numerous reports on SnS-based thin film solar cells with various buffer layers, including SnS 2 , 2 CdO, 3 Cd 2 SnO 4 , 3 CdS, [4][5][6][7][8][9][10] Cd 1Àx Zn x S, 7 ZnO, 11,12 TiO 2 , 13 PbS, 14 and a-Si. 15 The prevalent low efficiencies can be attributed to various sources, such as bulk material impurities and defects, interface trap states, and notably unfavorable heterojunction band alignment.…”