The behaviour of Na implanted into Mo thin films during annealing

Incorporation of alkali metals in chalcogenide solar cells

“…It has been theoretically proposed [91] and experimentally verified [92] that the mechanism responsible for Na diffusion is a H þ /Na þ ion exchange process and that the H þ is being stored in the Mo layer during air exposure whereas the source of Na is Na 2 O present in the glass [93]. The diffusion of Na from the SLG through the Mo proceeds via oxygenated Mo grain boundaries [92,94] and it has also been shown that oxygenated Mo layers provide CIGSe with higher Na concentrations [57,95]. It is worth mentioning that the amount of Na that diffuses is of Table 2 Typical composition of SLG (only the main constituents are given) [88].…”

Sodium-doped molybdenum back contacts for flexible Cu(In,Ga)Se2 solar cells

“…Consequently, the difference in Na signal peaks and valleys of the MoNa3 (with CIGS) might be underestimated in comparison to the MoNa3 (without CIGS) sample. Secondly, it is believed that Na preferentially diffuses through grain boundaries into the CIGS layer [19,20] and therefore is present at internal back contact interfaces as well. In this respect, the obtained ToF-SIMS result in Fig.…”

Thin‐Film Solar Cells and Modules

“…CuInSe 2 may be the only I -III -V chalcopyrite material that has the broad single -phase regime. Another critical issue in the growth of CuInSe 2 -based materials is the incorporation of Na into the fi lm that modifi es the growth habit of the fi lm and appears to reside at the grain boundaries and improves the properties of the solar cell device [43] . The soda lime glass substrate provides a source of Na, which diffuses from the glass thru the Mo contact into the growing CuInSe 2 -based fi lm.…”