TY  - JOUR
AU  - Gatz, S.
AU  - Dullweber, T.
AU  - Mertens, V.
AU  - Einsele, F.
AU  - Brendel, R.
TI  - Firing stability of SiN(y)/SiN(x) stacks for the surface passivation of crystalline silicon solar cells
JO  - Solar energy materials & solar cells
VL  - 96
SN  - 0927-0248
CY  - Amsterdam
PB  - North Holland
M1  - PreJuSER-19932
SP  - 180 - 185
PY  - 2012
N1  - The authors thank M. Perutz, S. Braunig, S. Spatlich and S. Wyczanowski for the sample preparation. This work was supported by the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety under Contract No. 0327529A, which is gratefully acknowledged.
AB  - In the photovoltaic industry contacts to crystalline silicon are typically formed by firing of screen-printed metallization pastes. However, the stability of surface passivation layers during high temperature contact formation is a major challenge. Here, we investigate the thermal stability of the surface passivation by amorphous silicon nitride double layers (SiNy/SiNx). The SiNy passivation layer is silicon rich with refractive index larger than 3. Whereas the SiNx capping layer has a refractive index of 2.05. Compared to pure hydrogenated amorphous silicon, the nitrogen in the SiNy passivation layer improves the firing stability. We achieve an effective surface recombination velocity after a conventional co-firing process of (5.2 +/- 2) cm/s on p-type (1.5 Omega cm) FZ-silicon wafers at an injection density of 10(15) cm(-3). An analysis of the improved firing stability is presented based on FTIR and hydrogen effusion measurements. The incorporation of an SiNy/SiNx stack into the passivated rear of Cz silicon screen-printed solar cells results in an energy conversion efficiency of 18.3% compared to reference solar cells with conventional aluminum back surface field showing 17.9% efficiency. The short circuit current density increases by up to 0.8 mA/cm(2) compared to conventional solar cells due to the improved optical reflectance and rear side surface passivation. (C) 2011 Elsevier By. All rights reserved.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000298534000025
DO  - DOI:10.1016/j.solmat.2011.09.051
UR  - https://juser.fz-juelich.de/record/19932
ER  -