Low‐Cost Copper Zinc Tin Sulfide Counter Electrodes for High‐Efficiency Dye‐Sensitized Solar Cells

Abstract

A copper zinc tin sulfide (CZTS) semiconductor can be used as an effective counter‐electrode (CE) material in place of platinum metal, yielding low‐cost, high‐efficiency dye‐sensitized solar cells (DSSCs). CZTS nanocrystals were synthesized and then spin‐coated on fluorine‐doped tin oxide (FTO) glass. After selenization, the power conversion efficiency of the resulting DSSC was comparable that with a Pt CE.

Rational screening low-cost counter electrodes for dye-sensitized solar cells

“…Unfortunately, the disadvantages such as the high cost and low abundance greatly restrict the large-scale application of Pt in DSCs [6][7][8][9] . Thus, several Pt-free alternative materials have been explored as CEs in DSCs, such as carbon materials 8,10 , conductive organic polymers 6,11 and inorganic semiconductor materials including metal sulfides 12,13 , metal nitrides 14,15 , metal carbides 16,17 , metal oxides 18 and copper zinc tin sulfide 19 and so on. Recently, Wu et al 20 synthesized three classes (carbides, nitrides and oxides) of nanoscaled earlytransition metal catalysts and applied them in DSC systems as CE catalysts to replace the expensive Pt.…”

A review on applications of Cu2ZnSnS4 as alternative counter electrodes in dye-sensitized solar cells

“…Therefore, development of phase pure CZTS crystals are significantly depending on the methods used to prepare the material. [99][100][101][102][103][104][105][106] As it was reported in theoretical studies of CZTS by the effective medium theory, the secondary phases of Cu 2 S, SnS can cause engineering of the band gap and will influence on light absorption properties of the material. 107 Depending on fill factor of some of the secondary phases, intermediate bands can be formed also.…”

“…45,55,64,97,100,[112][113][114][115][116][117][118][119][120][121][122][123][124] Performance of CZTS could be enhanced after treatment with TiCl 4 , making composite with another alternative electro-catalysts such as graphene, carbon or may be variation in the precursor concentration or film deposition mechanism. In situ fabricated CZTS film was shown periodic deposition upon tuning the concentration of CZTS precursor and ethanol during solvothermal synthesis process and designated as CZTS 1,2,3 4, and 5.…”

“…64,115 Partial replacement of S with Se could lead to the efficiency enhancement to 7.52 % as reported by . 100 Kong et al (2013) has also studied performance of CZTS according to synthesis of one pot route where wurtzite and kesterite both the phases are evaluated to understand the effect of phase purity towards CE application and wurzite phase of CZTS shows enhanced efficiency than kesterite even better than Pt. 120 Spray coated CZTS films are also capable to deliver effective replacement of Pt as reported by Swami et al (2014).…”

“…For CZTS synthesis, as the solubility of intermediates decreases in the following order: ZnS > SnS > SnS 2 > CuS > Cu 2 S ion exchange of pre-deposited ZnS with tin ion first and then copper ion could be favorable. 50 The final reaction could take place under heat treatment as per the equation (1) 100 Xie et al (2013) has already reported that tuning the morphology can directly affect performance of CE by variation of concentration of Zn 2+ during the synthesis. 130 Besides that, variation of molar concentration of [Cu 2+ ]/[Zn 2+ ] has also remarkably influence on the overall band gap, as reported by .…”