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P. 245
The impact of atmospheric species
vessels at all times, and was not clearly lower for the CO containing solutions than for
2
the N and O based vessels. During the degradation period, the pH of all vessels slowly
2
2
rose with approximately 0.5 to 1 pH point, but this was observed for most conditions as
well as the reference vessel, so it is assumed that this is within the measurement error.
The samples were all exposed to these conditions for 4/16/21/17/41/40/44/88/69
hours, counting up to a total of 340 hours.
Two samples were used as references: One sample was kept in the glovebox in an
argon atmosphere, while the other one was exposed to air for approximately 1560
hours. The sample names as used in this chapter are shown in Table 8.1 .
Table 8.1 Degradation conditions for the CIGS solar cells and the sample abbrevia-
tion used in this article.
Exposure conditions Sample name
Argon glovebox Reference
Air Air
Non-purged H 2 O (containing small quantities of air) H 2 O
H 2 O purged with N 2 H 2 O/N 2
H 2 O purged with O 2 H 2 O/O 2
H 2 O purged with air H 2 O/air
H 2 O purged with N 2 and 250 ppm CO 2 H 2 O/CO 2 /N 2
8.2.3 Characterisation of film properties
The optical, structural and electrical properties were determined by a number of
techniques before, during and after degradation. The measurements during the
degradation period were obtained by removal of the samples from the vessels, after
which they were dried and measured. The executed measurements are IV, EQE, SEM,
SIMS and lock-in thermopgraphy measurements and photography.
IV (current-voltage) measurements were obtained using an OAI TriSol Solar Simulator
attached to a Keithley SourceMeter 2400 and controlled using IV runner software,
version 1.4.0.6. The series resistance has been calculated from the last four points of
the IV measurement (+0.70 to +0.75 V), instead of at V, while the shunt resistances
oc
have been determined in a voltage range from -0.3 V to -0.06 V.
The spectral response (SR), and therefore also the external quantum efficiency (EQE),
were measured using a home-built SR setup at ECN in Eindhoven. The short circuit
current and efficiency were corrected for all degradation times based on the ratios
243
vessels at all times, and was not clearly lower for the CO containing solutions than for
2
the N and O based vessels. During the degradation period, the pH of all vessels slowly
2
2
rose with approximately 0.5 to 1 pH point, but this was observed for most conditions as
well as the reference vessel, so it is assumed that this is within the measurement error.
The samples were all exposed to these conditions for 4/16/21/17/41/40/44/88/69
hours, counting up to a total of 340 hours.
Two samples were used as references: One sample was kept in the glovebox in an
argon atmosphere, while the other one was exposed to air for approximately 1560
hours. The sample names as used in this chapter are shown in Table 8.1 .
Table 8.1 Degradation conditions for the CIGS solar cells and the sample abbrevia-
tion used in this article.
Exposure conditions Sample name
Argon glovebox Reference
Air Air
Non-purged H 2 O (containing small quantities of air) H 2 O
H 2 O purged with N 2 H 2 O/N 2
H 2 O purged with O 2 H 2 O/O 2
H 2 O purged with air H 2 O/air
H 2 O purged with N 2 and 250 ppm CO 2 H 2 O/CO 2 /N 2
8.2.3 Characterisation of film properties
The optical, structural and electrical properties were determined by a number of
techniques before, during and after degradation. The measurements during the
degradation period were obtained by removal of the samples from the vessels, after
which they were dried and measured. The executed measurements are IV, EQE, SEM,
SIMS and lock-in thermopgraphy measurements and photography.
IV (current-voltage) measurements were obtained using an OAI TriSol Solar Simulator
attached to a Keithley SourceMeter 2400 and controlled using IV runner software,
version 1.4.0.6. The series resistance has been calculated from the last four points of
the IV measurement (+0.70 to +0.75 V), instead of at V, while the shunt resistances
oc
have been determined in a voltage range from -0.3 V to -0.06 V.
The spectral response (SR), and therefore also the external quantum efficiency (EQE),
were measured using a home-built SR setup at ECN in Eindhoven. The short circuit
current and efficiency were corrected for all degradation times based on the ratios
243
