Cu2SnS3 thin films deposited by spin coating route: a promise candidate for low cost, safe and flexible solar cells

Abstract

Thin films of Cu 2 SnS 3 (CTS) was successfully grown on glass substrates by sol-gel spin coating technique. In this work, the effect of drying time on structural, morphological and optical characteristics is investigated while drying temperature was kept at 300°C. The samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-Vis-NIR spectroscopy and four probe analysis. The XRD patterns of the samples proved the polycrystalline nature and the formation of pure cubic Cu 2 SnS 3 structure with (111) preferential orientation. No peak referring to other binary or ternary phases were detected in the patterns. The average crystallite sizes calculated using the DebyeScherrer formula was about 7.5 nm. The AFM and SEM images revealed that the CTS films have continuous and dense morphology. The films roughness increases from 8 to 68 nm with increasing drying time from 2 to 10 min. The thin films absorption coefficients were in the range 0.66 9 10 5 -1.38 9 10 5 cm -1 at 2.14 eV. We found that by increasing the drying time, the sheet resistance increased from 22 to 574 kX and the direct optical band gap increased from 1.19 to 1.65 eV. The synthesised material seems to be a good candidate for flexible, cheap and friendly environment solar cells applications.

Thin Films Deposited by Spin Coating Technique: Review

“…Morphology study was performed using the atomic force microscopy (AFM) tool. Spin-coated films were rough compact without holes, indicating they are suitable to avoid shunting problems in solar cells [67]. A bigger grain size could be observed, reducing recombination at grain boundaries and involving carrier transport within the grain.…”

Precursor Molarity Influence on Sprayed Mo-doped ZnO Films for solar cells

“…In general, the quality of the absorber decides performance of the device. The collection of more number of charge carriers is mainly depends on the uniform and homogeneous surface of the absorber layer in which no voids (17) , also decrease of recombination losses in the short circuit current (18,19) . Furthermore, the main problem is the deep absorber defects, which reduce the saturation current density (Jo) and the open circuit voltage, leading to a reduced duty cycle.…”

Solution-processed extremely thin films of Cu2SnS3 nanoparticles for planar heterojunction solar cells

“…Although vacuum-based methods result in efficient solar cells, these methods normally suffer from the complicated and high cost facilities. Non-vacuum based solution methods such as spray pyrolysis [8,16], nanoparticle-ink deposition [9,17], chemical bath deposition [18] and molecular precursor solution method [19][20][21][22][23][24] have been used for low cost and scalable fabrication of CTS thin films for solar cells. Among these solution methods, molecular precursor solution method is of great importance because it is easy to control composition in the resulting film and avoid the complex steps associated with nanocrystal synthesis.…”