Transparent Conducting Oxide Free Backside Illuminated Perovskite
Solar Cells
Supporting information
Calculation of the costs for each part of the perovskite solar cells based on FTO
substrate
In order to calculate the cost of each part of the FTO-based perovskite solar cell, we
suppose the substrate is 1cm×1cm FTO (NSG, 15cm×20cm, 75￥). A layer of 500nm
thick TiO2 nanoparticle film with a porosity of 60% is prepared on FTO and the pores
are fully filled with CH3NH3PbI3 perovskites. Then, a layer of 200nm thick
Spiro-OMeTAD is deposited on perovskites. The gold electrode is set as 80nm. All of
the chemicals are obtained from Yingkou OPV Tech New Energy Co., Ltd. The
estimation of the cost for Ti foil-based perovskite solar cell was almost in the same
way. The major difference is the gold electrode for this structure is much more thinner,
which was about 10nm in thickness. The costs of each part of the perovskite solar
cells are shown in table S1. It can be seen easily that the cost of the our device(￥0.19)
is much cheaper than that of FTO-based structure(￥0.53).
Table S1. Costs of each part of the perovskite solar cell.
Components
FTO
TiO2
perovskite
Spiro-OMeTAD
(FTO based)
Gold
Total cost
electrode
Costs(￥)
0.25
1*10-4
2*10-3
0.15
0.13
0.53
Components
Ti
-
Perovskite
Spiro-OMeTAD
Gold
Total cost
(Ti based)
Costs(￥)
electrode
0.02
-
2*10-3
0.15
0.02
0.19
Fig. S1 shows the cost proportion of each part in total cost of the FTO-based
perovskite solar cells. As the costs of TiO2 and perovskites are little, they are not
exhibited in Fig. S1. It can be seen that Spiro-OMeTAD and FTO make up most of
the total cost of the perovskite solar cell. And the cost of FTO accounts for 47% of the
total costs.
25%
47%
28%
FTO
Spiro-OMeTAD
Au
Figure S1. The proportion of the total cost for each part of the FTO–based perovskite
solar cell device
Figure S2. Top view SEM images of gold electrode with different deposition time a)
30s, b) 60s, c) 90s, d) 120s.
Table S2: Photovoltaic parameters of ten devices measured under 100 mW cm-2
simulated AM1.5G irradiation
cell
Jsc (mA/cm2)
Voc (V)
FF
η(%)
1
11.2
0.755
0.574
4.85
2
11.3
0.751
0.605
5.15
3
10.7
0.837
0.588
5.27
4
9.56
0.781
0.627
4.68
5
10.2
0.833
0.538
4.57
6
11.2
0.755
0.571
4.83
7
11.2
0.825
0.452
4.18
8
10.5
0.817
0.530
4.55
9
11.6
0.696
0.546
4.41
10
11.7
0.740
0.506
4.38
Table S3. Square resistance of Au films with different deposition time on
Spiro-OMeTAD
Structure
Square resistance
Spiro-OMeTAD
130000Ω/sq
Spiro-OMeTAD+30s Au film
1488 Ω/sq
Spiro-OMeTAD+60s Au film
34 Ω/sq
Spiro-OMeTAD+90s Au film
15 Ω/sq
Spiro-OMeTAD+120s Au film
9 Ω/sq
Figure S3. Stability of the photovolatic device as stored in atmospheric enviroment