Importance of atmospheric aerosol pollutants on the degradation of Al₂O₃ encapsulated Al‐doped zinc oxide window layers in solar cells

Abstract

Atmospheric aerosol pollutants are considered for the first time for the durability evaluation of non-metallic photovoltaic materials on the example of pristine and Al 2 O 3 -encapsulated Al-doped zinc oxide (AZO) window layers. The AZO samples were exposed to a varied temperature and humidity cycle, completed or not by a daily deposition of (NH 4 ) 2 SO 4 or NaCl aerosols, typical pollutants in rural and marine environments, respectively. The samples exposed with and without the pollutants were compared after 1 and 2 weeks of the test. Optical transmittance and conductivity significantly degraded only for the samples exposed with the pollutants. Raman

Synergistic effect between molybdenum back contact and CIGS absorber in the degradation of solar cells

“…The XPS results are therefore consistent with the visual observations and with literature 7 that while a 25 nm thick ALD-Al 2 O 3 layer strongly limited the degradation of "No pollutant" samples (subjected only to the variations of temperature and humidity), it was inefficient in the presence of all the tested salts. The XPS results of this work are also consistent with the previous works, demonstrating that a 25 nm thick Al 2 O 3 encapsulation on the AZO windows layers successfully passed the 1000 h DH test11 but degraded in the presence of NaCl or (NH 4 ) 2 SO 4 aerosols and temperature and humidity cycling 7. XPS also confirmed that Mo was mainly present as Mo (VI) oxides (Mo 3d 5/2 binding energies at 232.4 ± 0.1 eV and 233.3 ± 0.1 eV).32 The unexposed SLG/Mo/CIGS/Al 2 O 3 configuration revealed the presence of the Al 2 O 3 encapsulation layer without any detectable signal from the underlying CIGS layer.…”

“…According to the literature, the main cause of the efficiency loss of CIGS cells in the presence of humidity can be ascribed to the resistivity increase of the AZO layer 12–14 . Our previous work 7 has also demonstrated that the atmospheric aerosols can crucially decrease the life time of AZO. The combined effect of humidity and atmospheric aerosol pollution on other layers of the CIGS cell, in particular the back contact and absorber, was not reported in the literature to the extent of our knowledge.…”

“…To further replicate the outdoor conditions and in particular dew phenomena, we have recently proposed a novel degradation protocol. 7 It not only considers daily variations of temperature and humidity but also takes into account outdoor pollutants, well-known as corrosion promoters in corrosion science but rarely included in aging test in PV. [7][8][9] To understand degradation processes, it is necessary to consider the complete cell architecture because the stability of each layer and interface can affect the stability of other layers and the overall cell performance.…”

“…Temperature effects are also studied by thermal cycling: Temperature varies from −40 ± 2°C to 85 ± 2°C for 20 cycles with a maximum duration of 6 h/cycle (also described in Standard EN 61215, no specification for humidity 6 ) in order to better mimic daily or seasonal temperature variations. To further replicate the outdoor conditions and in particular dew phenomena, we have recently proposed a novel degradation protocol 7 . It not only considers daily variations of temperature and humidity but also takes into account outdoor pollutants, well‐known as corrosion promoters in corrosion science but rarely included in aging test in PV 7–9 …”

“…To further replicate the outdoor conditions and in particular dew phenomena, we have recently proposed a novel degradation protocol 7 . It not only considers daily variations of temperature and humidity but also takes into account outdoor pollutants, well‐known as corrosion promoters in corrosion science but rarely included in aging test in PV 7–9 …”