Effects of sulfurization and Cu/In ratio on the performance of the CuInS₂solar cell

Abstract

SUMMARY Photovoltaic CuInS2 (CIS) thin films were prepared from thermally evaporated Cu/In precursors, having various Cu/In ratios, under different sulfurization conditions. The sulfurization was carried out in a quartz tube furnace under a steady or flowing H2S/Ar gas mixture at various temperatures ranging from 450 to 550 °C. The effects of the Cu/In ratio and sulfurization condition on the grain size, surface morphology, surface roughness, microstructure and defect formation of the resulting CIS films were examined. It was found that the effects depend on the processing conditions. Particularly, we show that sub‐bandgap generated defects can be inferred by photoluminescence data. Selected CIS thin films were used as absorber layers for the fabrication of thin film solar cells. The best solar cell efficiency of 6.29% was obtained from the 500 °C‐sulfurized absorber layer having a Cu/In ratio of 1.8. Effect of absorber layer characteristics on the cell efficiency was also discussed. Copyright © 2013 John Wiley & Sons, Ltd.

Postdeposition Sulfurization of CuInSe2 Solar Absorbers by Employing Sacrificial CuInS2 Precursor Layers

“…The dashed lines indicate the Raman shifts corresponding to different phases reported elsewhere. [ 17,19,22,23,45 ]…”

“…This feature can be explained by the presence of a spinel CuIn 5 S 8 phase that has been detected in similar sputtered materials before. [ 19 ] However, a contribution from In 2 S 3 cannot be excluded.. [ 20,21 ] The spinel CuIn 5 S 8 (or In 2 S 3 ) phase is not observed in the samples treated with Se, which means that this compound has been transformed into other phases. A possible route is that it was consumed by supplying S (and Cu) into the CISe layer underneath, while the remaining In reacted with Se from the annealing atmosphere (or with Se expelled from CISe upon S incorporation).…”

Cu2ZnSnS4 absorption layers with controlled phase purity

“…Furthermore, some minor phases often cannot be detected by XRD. Therefore Raman analysis is used as a supplementary tool as reported earlier 31 33 34 . Fig.…”

Effects of Preparation Conditions on the CuInS2 Films Prepared by One‐Step Electrodeposition Method

“…Preparation methods of CuInS 2 film mainly include sputtering [6], evaporation [7], spray pyrolysis [8,9], chemical bath deposition [10], and electrodeposition [11][12][13][14][15][16]. Among these methods, sputtering and evaporation are two main methods for industrial production [7,[17][18][19][20]. However, expensive equipment is necessary for providing vacuum environment in the two methods, which limit their use in the production of large-area CuInS 2 films.…”