New insights in the electrodeposition mechanism of CuInSe² thin films for solar cell applications

Abstract

The electrodeposition of CuInSe2, one of the most appropriate absorber for thin layer photovoltaic solar cells, is investigated with a rotating disc electrode by voltametry, steady‐state polarization and electrochemical impedance spectroscopy in dilute acidic solutions. Three main potential domains are distinguished. At low cathodic polarizations, binary Cu‐Se compounds are deposited. Indium starts to incorporate beyond a potential threshold which is associated with a current peak similar to a passivation peak and with impedance diagrams showing a negative polarisation resistance. For more negative potentials the impedance diagrams exhibit mainly characteristic features corresponding to charge transfer under diffusional control. A reaction path is proposed. These results are discussed in terms of general behavior of multinary compound deposition. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Effects of sodium sulfamate on electrodeposition of Cu(In,Ga)Se2 thin film

“…(13)) [27,39,40], which is also verified by the film structure in the next section. In this case, whether Ga 2 Se 3 proceeds via similar reaction to form CuGaSe 2 or CuInGaSe 2 still needs further evidence.…”

A short review on the advancements in electroplating of CuInGaSe2 thin films

“…However, after selective dissolution of elemental Se, the atomic ratio of CuSe platelets [Se/Cu] was found to be close to unity (Fig. 10c) [106]. Increased Se concentration (over CuSe platelets) contributes to the formation of CuSe 2 phase.…”

“…Irrespective of the immersion time, no peak corresponding to Se (254 cm −1 ) was observed. Only characteristic Raman peaks corresponding to Cu 3 Se 2 (106,141,197, and 216 cm −1 ) and Cu 2 Se (261 cm −1 ) were observed [105]. Hence, at lower cathodic potential, Cu-Se binary co-exists as mixtures of Cu 3 Se 2 , Cu 2 Se, CuSe, and Se(0) [107,108].…”

“…Excess selenium over CuSe phase is a perquisite of the indium incorporation at lower cathodic potential [106]. However, the inclusion of In through such surface-induced reactions (at lower cathodic potential) is often limited which is ascribed to the increased electrical resistance of the surface due to poor reacting nature of Se(0) species [111].…”

Applications of Electrochemistry in the Fabrication and Characterization of Thin‐Film Solar Cells

“…Chassaing et al . [107] proposed the following reaction scheme based on their results: [109] . This proposed mechanism requires, of course, that the electrode surface should be continually refreshed in Cu 2 Se and Se.…”