Table 2: Element analysis of Cs2CO3 film with different time of UV-Ozone treatment.

Elements O Si In Sn Cs O/Cs (mol)

5 min Wt % 22.3122.41 31.29 2.07 21.92 8.45
At % 52.68 30.14 10.30 0.66 6.23

10 min Wt % 26.95 26.21 25.50 2.04 19.29 11.59
At % 56.11 31.08 7.40 0.57 4.84

15 min Wt % 22.37 27.91 28.93 3.21 17.57 10.56
At % 49.88 35.45 8.99 0.97 4.72

20 min Wt % 46.44 27.26 12.71 0.85 12.75 30.22
At % 71.02 23.75 2.71 0.18 2.35

(Wt %: weight percent; At %: elemental mol percent; O/Cs: Mol ratio.)