Details
| Original language | English |
|---|---|
| Pages (from-to) | 436-440 |
| Number of pages | 5 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 120 |
| Issue number | PART A |
| Publication status | Published - 2014 |
Abstract
Aluminum oxide provides an excellent surface passivation on p- and n-type crystalline silicon. On n-type silicon, however, the effective excess carrier lifetime τeff is often found to be injection dependent. Our experimental results show that, in our case, this effect depends mainly on the size of the lifetime samples. The fixed negative charges present at the Al 2O3/c-Si interface induce an inversion layer at the surface, which results in a p-n-junction close to the surface of the sample and the inversion layer couples the sensing area with the poorly passivated or damaged edge of the sample. For smaller samples stronger injection-dependent lifetimes are measured, whereas large samples show a smaller injection dependence. In addition, photoconductance-calibrated photoluminescence lifetime images show that for low injection levels the lifetime decreases towards the sample edge. Device simulations for different sample sizes including the edge recombination are in agreement with the measured injection-dependent lifetimes. Therefore, it is necessary to use sufficiently large samples or decouple the sensing area form the edge when evaluating the injection dependence of the lifetime. For the samples used in this contribution, the injection dependence of the lifetime did not even fully vanish for an edge length of 12.5 cm.
Keywords
- Aluminum oxide, Charge carrier lifetime, Modeling, Silicon, Surface passivation
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Surfaces, Coatings and Films
Sustainable Development Goals
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In: Solar Energy Materials and Solar Cells, Vol. 120, No. PART A, 2014, p. 436-440.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Injection dependence of the effective lifetime of n-type Si passivated by Al2O3
T2 - An edge effect?
AU - Veith, Boris
AU - Ohrdes, Tobias
AU - Werner, Florian
AU - Brendel, Rolf
AU - Altermatt, Pietro P.
AU - Harder, Nils Peter
AU - Schmidt, Jan
N1 - Funding Information: The authors thank M. Kessler for fruitful discussions. Funding was provided by the State of Lower Saxony and the German Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU) under Contract no. 0325050 (“ALD”).
PY - 2014
Y1 - 2014
N2 - Aluminum oxide provides an excellent surface passivation on p- and n-type crystalline silicon. On n-type silicon, however, the effective excess carrier lifetime τeff is often found to be injection dependent. Our experimental results show that, in our case, this effect depends mainly on the size of the lifetime samples. The fixed negative charges present at the Al 2O3/c-Si interface induce an inversion layer at the surface, which results in a p-n-junction close to the surface of the sample and the inversion layer couples the sensing area with the poorly passivated or damaged edge of the sample. For smaller samples stronger injection-dependent lifetimes are measured, whereas large samples show a smaller injection dependence. In addition, photoconductance-calibrated photoluminescence lifetime images show that for low injection levels the lifetime decreases towards the sample edge. Device simulations for different sample sizes including the edge recombination are in agreement with the measured injection-dependent lifetimes. Therefore, it is necessary to use sufficiently large samples or decouple the sensing area form the edge when evaluating the injection dependence of the lifetime. For the samples used in this contribution, the injection dependence of the lifetime did not even fully vanish for an edge length of 12.5 cm.
AB - Aluminum oxide provides an excellent surface passivation on p- and n-type crystalline silicon. On n-type silicon, however, the effective excess carrier lifetime τeff is often found to be injection dependent. Our experimental results show that, in our case, this effect depends mainly on the size of the lifetime samples. The fixed negative charges present at the Al 2O3/c-Si interface induce an inversion layer at the surface, which results in a p-n-junction close to the surface of the sample and the inversion layer couples the sensing area with the poorly passivated or damaged edge of the sample. For smaller samples stronger injection-dependent lifetimes are measured, whereas large samples show a smaller injection dependence. In addition, photoconductance-calibrated photoluminescence lifetime images show that for low injection levels the lifetime decreases towards the sample edge. Device simulations for different sample sizes including the edge recombination are in agreement with the measured injection-dependent lifetimes. Therefore, it is necessary to use sufficiently large samples or decouple the sensing area form the edge when evaluating the injection dependence of the lifetime. For the samples used in this contribution, the injection dependence of the lifetime did not even fully vanish for an edge length of 12.5 cm.
KW - Aluminum oxide
KW - Charge carrier lifetime
KW - Modeling
KW - Silicon
KW - Surface passivation
UR - http://www.scopus.com/inward/record.url?scp=84888312268&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2013.06.049
DO - 10.1016/j.solmat.2013.06.049
M3 - Article
AN - SCOPUS:84888312268
VL - 120
SP - 436
EP - 440
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
SN - 0927-0248
IS - PART A
ER -