Abstract
We report on the electrical and physical properties of Cu 2ZnSnSe4 (CZTSe) solar cells consisting of an absorber layer fabricated by selenization of sputtered Cu, Zn, Sn multilayers. Cross-section scanning electron microscopy images show that the polycrystalline absorber layers are approximately 1 μm thick and that the typical grain size is of the order of 1 μm. Energy-dispersive X-ray spectroscopy measurements show Cu-poor and Zn-rich compositions with Cu/(Zn + Sn) ~ 0.8 and Zn/Sn ~ 1.2. Solar cells are fabricated out of this absorber material using a standard process flow for chalcogenide solar cells. Under AM1.5 G illumination, the best 1 × 1 cm2 CZTSe solar cell shows an efficiency of 6.3% with a maximum short circuit current of 31.3 mA/cm2, an open circuit voltage of 0.39 V and a fill factor of 52%. Doping density of the absorber layers is derived using the drivel level capacitance profiling (DLCP) technique, showing low p-type doping density which seems to increase exponentially with the Zn/Sn ratio. Comparing the values obtained from DLCP to the ones derived from Mott-Schottky plots of the same devices, it is shown that for CZTSe care has to be taken when deriving the doping density. Similar to copper indium gallium selenide junctions, Mott-Schottky plots overestimate the amount of free carriers in the buffer due to the presence of fast defect states inside the bandgap.
| Original language | English |
|---|---|
| Pages (from-to) | 348-352 |
| Number of pages | 5 |
| Journal | Thin Solid Films |
| Volume | 535 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 15 May 2013 |
| Externally published | Yes |
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Keywords
- CuZnSnSe
- Kesterites
- Thin film photovoltaics
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Materials Chemistry
- Metals and Alloys
- Surfaces, Coatings and Films
- Surfaces and Interfaces
Cite this
Electrical characterization of Cu2ZnSnSe4 solar cells from selenization of sputtered metal layers. / Brammertz, Guy; Ren, Yi; Buffiere, Marie; Mertens, Sofie; Hendrickx, Jurgen; Marko, Hakim; Zaghi, Armin E.; Lenaers, Nick; Köble, Christine; Vleugels, Jef; Meuris, Marc; Poortmans, Jef.
In: Thin Solid Films, Vol. 535, No. 1, 15.05.2013, p. 348-352.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Electrical characterization of Cu2ZnSnSe4 solar cells from selenization of sputtered metal layers
AU - Brammertz, Guy
AU - Ren, Yi
AU - Buffiere, Marie
AU - Mertens, Sofie
AU - Hendrickx, Jurgen
AU - Marko, Hakim
AU - Zaghi, Armin E.
AU - Lenaers, Nick
AU - Köble, Christine
AU - Vleugels, Jef
AU - Meuris, Marc
AU - Poortmans, Jef
PY - 2013/5/15
Y1 - 2013/5/15
N2 - We report on the electrical and physical properties of Cu 2ZnSnSe4 (CZTSe) solar cells consisting of an absorber layer fabricated by selenization of sputtered Cu, Zn, Sn multilayers. Cross-section scanning electron microscopy images show that the polycrystalline absorber layers are approximately 1 μm thick and that the typical grain size is of the order of 1 μm. Energy-dispersive X-ray spectroscopy measurements show Cu-poor and Zn-rich compositions with Cu/(Zn + Sn) ~ 0.8 and Zn/Sn ~ 1.2. Solar cells are fabricated out of this absorber material using a standard process flow for chalcogenide solar cells. Under AM1.5 G illumination, the best 1 × 1 cm2 CZTSe solar cell shows an efficiency of 6.3% with a maximum short circuit current of 31.3 mA/cm2, an open circuit voltage of 0.39 V and a fill factor of 52%. Doping density of the absorber layers is derived using the drivel level capacitance profiling (DLCP) technique, showing low p-type doping density which seems to increase exponentially with the Zn/Sn ratio. Comparing the values obtained from DLCP to the ones derived from Mott-Schottky plots of the same devices, it is shown that for CZTSe care has to be taken when deriving the doping density. Similar to copper indium gallium selenide junctions, Mott-Schottky plots overestimate the amount of free carriers in the buffer due to the presence of fast defect states inside the bandgap.
AB - We report on the electrical and physical properties of Cu 2ZnSnSe4 (CZTSe) solar cells consisting of an absorber layer fabricated by selenization of sputtered Cu, Zn, Sn multilayers. Cross-section scanning electron microscopy images show that the polycrystalline absorber layers are approximately 1 μm thick and that the typical grain size is of the order of 1 μm. Energy-dispersive X-ray spectroscopy measurements show Cu-poor and Zn-rich compositions with Cu/(Zn + Sn) ~ 0.8 and Zn/Sn ~ 1.2. Solar cells are fabricated out of this absorber material using a standard process flow for chalcogenide solar cells. Under AM1.5 G illumination, the best 1 × 1 cm2 CZTSe solar cell shows an efficiency of 6.3% with a maximum short circuit current of 31.3 mA/cm2, an open circuit voltage of 0.39 V and a fill factor of 52%. Doping density of the absorber layers is derived using the drivel level capacitance profiling (DLCP) technique, showing low p-type doping density which seems to increase exponentially with the Zn/Sn ratio. Comparing the values obtained from DLCP to the ones derived from Mott-Schottky plots of the same devices, it is shown that for CZTSe care has to be taken when deriving the doping density. Similar to copper indium gallium selenide junctions, Mott-Schottky plots overestimate the amount of free carriers in the buffer due to the presence of fast defect states inside the bandgap.
KW - CuZnSnSe
KW - Kesterites
KW - Thin film photovoltaics
UR - http://www.scopus.com/inward/record.url?scp=84878183383&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84878183383&partnerID=8YFLogxK
U2 - 10.1016/j.tsf.2012.10.037
DO - 10.1016/j.tsf.2012.10.037
M3 - Article
AN - SCOPUS:84878183383
VL - 535
SP - 348
EP - 352
JO - Thin Solid Films
JF - Thin Solid Films
SN - 0040-6090
IS - 1
ER -