Page 219 - Mirjam-Theelen-Degradation-of-CIGS-solar-cells
P. 219
The impact of alkali elements
Au Au 60 nm Au Au
1 µm
Al:ZnO Al:ZnO
i-ZnO 65 nm i-ZnO
CdS 50 nm CdS
Cu(In,Ga)Se 2 2 µm Cu(In,Ga)Se 2
Molybdenum 500 nm Molybdenum
SiN x
(200 nm)
Soda lime glass 1 mm Soda lime glass
Figure 7.2
Figure 7.1: Schematic cross-section of the alkali poor CIGS solar cells with
Schematic cross-section of the alkali-poor CIGS solar cells with a SiN x barrier as used in this study (left) and the alkali-rich
a SiN x barrier as used in this study (left) and the alkali rich sample (right)
sample (right) (not to scale).
(not to scale).
cells were deposited on a soda lime glass substrate with a SiN barrier in the same
x
deposition runs under exactly the same conditions. A schematic cross-section of the
samples is shown in Figure 7.2.
Six samples from both solar cell types were placed in the hybrid degradation setup,
which is described in chapter 3.3. There they were exposed to an atmosphere of 85 C
o
and 85% RH combined with 1000 W/m AM 1.5, which allowed the in-situ monitoring
2
of the degradation behaviour. Two samples were kept in a glovebox as reference
samples. The samples were degraded as is described in chapter 3.3. IV curves of
all solar cells were measured every 3 or 8 minutes. The temperature of all cells was
measured individually, since the cells are heated by the illumination: the actual sample
temperature was 107±1°C.
In order to study the progress of the degradation process, the degraded samples
were progressively removed from the setup. The first samples were removed after
165 hours (one sample per type), next samples after 365 hours (one sample per type),
then after 525 hours (one sample per type) and finally after 778 hours (three samples
per type). One sample showed strange results, including a very rapid increase of series
resistance and a relatively slow increase of the open circuit voltage, and was omitted
from this study. The alkali-poor solar cells in this study have a cell size of 0.33±0.03
cm , while the alkali-rich samples are 0.31±0.01 cm .
2
2
217
Au Au 60 nm Au Au
1 µm
Al:ZnO Al:ZnO
i-ZnO 65 nm i-ZnO
CdS 50 nm CdS
Cu(In,Ga)Se 2 2 µm Cu(In,Ga)Se 2
Molybdenum 500 nm Molybdenum
SiN x
(200 nm)
Soda lime glass 1 mm Soda lime glass
Figure 7.2
Figure 7.1: Schematic cross-section of the alkali poor CIGS solar cells with
Schematic cross-section of the alkali-poor CIGS solar cells with a SiN x barrier as used in this study (left) and the alkali-rich
a SiN x barrier as used in this study (left) and the alkali rich sample (right)
sample (right) (not to scale).
(not to scale).
cells were deposited on a soda lime glass substrate with a SiN barrier in the same
x
deposition runs under exactly the same conditions. A schematic cross-section of the
samples is shown in Figure 7.2.
Six samples from both solar cell types were placed in the hybrid degradation setup,
which is described in chapter 3.3. There they were exposed to an atmosphere of 85 C
o
and 85% RH combined with 1000 W/m AM 1.5, which allowed the in-situ monitoring
2
of the degradation behaviour. Two samples were kept in a glovebox as reference
samples. The samples were degraded as is described in chapter 3.3. IV curves of
all solar cells were measured every 3 or 8 minutes. The temperature of all cells was
measured individually, since the cells are heated by the illumination: the actual sample
temperature was 107±1°C.
In order to study the progress of the degradation process, the degraded samples
were progressively removed from the setup. The first samples were removed after
165 hours (one sample per type), next samples after 365 hours (one sample per type),
then after 525 hours (one sample per type) and finally after 778 hours (three samples
per type). One sample showed strange results, including a very rapid increase of series
resistance and a relatively slow increase of the open circuit voltage, and was omitted
from this study. The alkali-poor solar cells in this study have a cell size of 0.33±0.03
cm , while the alkali-rich samples are 0.31±0.01 cm .
2
2
217
