6. The stability of CIGS on an industrial scales

Degradation of modules at the moment, the highest conversion efficiency η of CIGS was 22.3% (Solar Frontier 2015) [32–38]. The three main parameters determining the cost competitiveness of electricity from PV panel is shown in Figure 15. The degradation rate per year is obtained by:

$$\text{Degradation } (\%) = \left(\frac{\eta\_{\text{initial}} - \eta\_{\text{final}}}{\eta\_{\text{initial}} \times \text{Time}}\right) \times 100\%. \tag{13}$$

Table 4 shows an overview of failure modules loading to CIGS module degradation and global categorization, when they are specific to CIGS or also observed for other thin-film modules. It was concluded that CIGS solar cells and modules are very sensitive to humidity. Furthermore, sensitivity to, for example, temperature (shocks), electrical bias, and illumination

Table 3. Literature overview of degradation rates (%/year) of CIGS modules obtained from field tests at different

has been found, but the impacts of these loads are not necessarily detrimental.

locations.

Figure 15. The three main parameters determining the cost competiveness of electricity from PV panels.

Some Essential Issues and Outlook for Industrialization of Cu-III-VI2 Thin-Film Solar Cells

http://dx.doi.org/10.5772/intechopen.77023

143

The time is given in year. Table 3 shows the recently tested modules vary from very stable (No degradation after 7 years) to vulnerable to outdoor exposure.

Degradation depends on many parameters such as module production technologies, module type, production year, the orientation of the panel, climate, and installation location, as well as installation parameters like system voltage.

Generally, the investigation of degradation process in CIGS solar cells and modules is the complex and definite identification of failure mechanisms can be complicated.

Some Essential Issues and Outlook for Industrialization of Cu-III-VI2 Thin-Film Solar Cells http://dx.doi.org/10.5772/intechopen.77023 143

Figure 15. The three main parameters determining the cost competiveness of electricity from PV panels.

as a function of TMGa flow rate and substrate temperature [1]. And the linear relationship of Ga/(Ga + In) with the TMGa flow rate to adjust the deposited film composition is particularly interesting. I could conclude from in Figure 12 that the Raman shift as a function of the film composition change of Cu/(Ga + In) from the micro-Raman spectroscopy. It is clear that the micro-Raman shift is sensitive to the composition change of the CIGS thin-films. If we combine the use of Mo-Sputtering for the film growth and its feedback monitoring with the Raman shift, a means to better control the stoichiometry of thin-film might be provided during the

Degradation of modules at the moment, the highest conversion efficiency η of CIGS was 22.3% (Solar Frontier 2015) [32–38]. The three main parameters determining the cost competitiveness of electricity from PV panel is shown in Figure 15. The degradation rate per year is obtained by:

The time is given in year. Table 3 shows the recently tested modules vary from very stable (No

Degradation depends on many parameters such as module production technologies, module type, production year, the orientation of the panel, climate, and installation location, as well as

Generally, the investigation of degradation process in CIGS solar cells and modules is the

complex and definite identification of failure mechanisms can be complicated.

ηinitial � Time 

� 100%: (13)

Degradation ð Þ¼ % <sup>η</sup>initial � <sup>η</sup>final

manufacturing steps (Figures 13 and 14).

142 Emerging Solar Energy Materials

6. The stability of CIGS on an industrial scales

Figure 14. Micro-Raman spectroscopy results on the composition of thin-films.

degradation after 7 years) to vulnerable to outdoor exposure.

installation parameters like system voltage.


Table 3. Literature overview of degradation rates (%/year) of CIGS modules obtained from field tests at different locations.

Table 4 shows an overview of failure modules loading to CIGS module degradation and global categorization, when they are specific to CIGS or also observed for other thin-film modules. It was concluded that CIGS solar cells and modules are very sensitive to humidity. Furthermore, sensitivity to, for example, temperature (shocks), electrical bias, and illumination has been found, but the impacts of these loads are not necessarily detrimental.


Table 4. Summary of failure as observed for CIGS.
