VARIATIONS in damp heat-induced degradation behavior of sputtered ZnO window layer for CIGS solar cells
2010
This paper presents our recent observations on variations in properties and damp heat (DH)-induced degradation
behavior for single-layer 2%Al-doped ZnO (AZO) and bilayer ZnO (BZO), which comprises 0.1-μm intrinsic ZnO (i-ZnO) and AZO, deposited on glass substrates using the same sputtering system and essentially identical deposition
conditions. BZO films with 0.12-μm AZO have been used on the National Renewable Energy Laboratory's (NREL's)
high-efficiency CuInGaSe 2 (CIGS) solar cells for years. For the as-deposited BZO films, the most apparent variations
appeared in notable peak shift in transmittance and reflectance spectra and ZnO (002) peak intensity and peak position in
X-ray diffraction. Location of substrates placed on the substrate holder platform contributed partly to the variations. For
the DH-degraded AZO and BZO, earlier films became highly resistive, porous, and 10~20 X thicker and showed
flattened transmittance spectra caused by a loss of free-carrier absorption. However, recent DH-exposed AZO and BZO
films also became highly resistive but exhibited only small changes in transmittance spectra, while the columnar grain
structure and film thickness remained nearly unchanged without porous features, but with granular particles formed on
the surfaces that increased in size with lengthening DH exposure time.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
0
References
10
Citations
NaN
KQI