Influence of compositionally induced defects on the vibrational properties of device grade Cu2ZnSnSe4 absorbers for kesterite based solar cells

Abstract

This work presents a detailed analysis of the impact of compositionally induced defects on the vibrational properties of Cu2ZnSnSe4 absorbers for kesterite based solar cells. Systematic changes in the intensity of the E and B modes located around the 170, 220, and 250 cm-1 frequency regions, which involve mostly cation vibrations, were observed and analyzed in relation to the occurrence of different kinds of defect clusters involving VCu, ZnCu, ZnSn, CuZn, and SnZn point defects. Additional changes are also interpreted in terms of the appearance of SnSe, ZnSe, and CuSe-like contributions at the 185 and 250 cm-1 spectral regions, respectively. The sensitivity of the Raman measurements to the presence of these kinds of defects corroborates the potential of Raman scattering for point defect assessment in these systems. © 2015 AIP Publishing LLCPeer ReviewedPostprint (published version

The importance of back contact modification in Cu2ZnSnSe4 solar cells: The role of a thin MoO2 layer

“…V Cu ] defect clusters [72]. In the case of the work of Dimitrievska et al, the changes in the Raman spectra were induced by compositional variations in the CZTSe absorbers, but in our particular case the compositional ranges are very similar (See Figure 5) is included in the S.I.…”

Towards high performance Cd-free CZTSe solar cells with a ZnS(O,OH) buffer layer: the influence of thiourea concentration on chemical bath deposition

“…This indicates that this layer has a very low S content, with a value S/(S+O) < 0.04 according to the dependence of the frequency of this peak on the S/(S+O) content reported in A. Polity et al [33] In the spectra from the 0.35 M and 0.40 M samples only CZTSe characteristic Raman peaks were observed. [34,35] This could be related with a loss of the resonant Raman excitation conditions when using the UV excitation line in these very thin layers because of the strong band gap bowing that takes place in Zn(O,S) alloys with S/(S+O) relative content close to 0.5. [33] In case of sample 0.50 M the ratio of first (at 347 cm -1 ) and second (at 692 cm -1 ) order ZnS like Raman peaks allows to make an estimation of the grain size in the layer of below 10 nm which is in agreement with the XPS estimated thickness below 9 nm.…”

Influence of Amorphous Silicon Carbide Intermediate Layer in the Back-Contact Structure of Cu2ZnSnSe4Solar Cells

“…Raman analysis for the front surface of the samples ( figure 3a) shows the typical peaks of CZTSe phase with good crystal quality and Cu poor content [28] (Figure 3(d)), which is correlated to a clear increase of V oc as it will be shown below.…”