Details
| Original language | English |
|---|---|
| Pages (from-to) | 292-295 |
| Number of pages | 4 |
| Journal | Solar Energy Materials and Solar Cells |
| Volume | 95 |
| Issue number | 1 |
| Publication status | Published - Jan 2011 |
| Externally published | Yes |
Abstract
We investigate sintering and reorganization of electrochemically etched mesoporous Ge layers. Sintering in nitrogen, forming gas, or argon atmospheres always yields a reorganized and oxidized porous layer. Water-insoluble Ge native oxides produced during etching do not hinder thermal reorganization, but evolve to water soluble oxides during annealing. Reorganized porous layers hence dissolve in subsequent water or HF dips. Sintering in hydrogen atmospheres removes native Ge oxides and prevents oxidation of porous layers. Porous layers with porosities less than 30% exhibit a compact closed surface after sintering, whereas porous layers with porosities exceeding 50% collapse. The porosity decreases linearly in a range of 57%45% for electrolyte concentrations and in a range of 3550 wt% for a specific resistivity of 0.013 Ω cm and an etching current density of 5 mA cm-2. We obtain porosities below 30% by using substrate resistivities in the 0.0150.030 Ω cm range, etching current densities below 2.5 mA cm-2 and an electrolyte concentration of HF 50 wt%.
Keywords
- Lift-off, Porous germanium, Sintering
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. 95, No. 1, 01.2011, p. 292-295.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Sintering and reorganization of electrochemically etched mesoporous germanium layers in various atmospheres
AU - Garralaga Rojas, E.
AU - Hensen, J.
AU - Baur, C.
AU - Brendel, R.
N1 - Funding Information: The authors would like to thank Bianca Gehring for the technical assistance. The financial support of this work by the German Ministry for Economy and Technology under Contract no. 50JR0641 is gratefully acknowledged. E. Garralaga Rojas specially thanks the European Space Agency for the financial support of his work in the framework of the Networking Partnering Initiative (Co. no. 20250/06/NL/GLC).
PY - 2011/1
Y1 - 2011/1
N2 - We investigate sintering and reorganization of electrochemically etched mesoporous Ge layers. Sintering in nitrogen, forming gas, or argon atmospheres always yields a reorganized and oxidized porous layer. Water-insoluble Ge native oxides produced during etching do not hinder thermal reorganization, but evolve to water soluble oxides during annealing. Reorganized porous layers hence dissolve in subsequent water or HF dips. Sintering in hydrogen atmospheres removes native Ge oxides and prevents oxidation of porous layers. Porous layers with porosities less than 30% exhibit a compact closed surface after sintering, whereas porous layers with porosities exceeding 50% collapse. The porosity decreases linearly in a range of 57%45% for electrolyte concentrations and in a range of 3550 wt% for a specific resistivity of 0.013 Ω cm and an etching current density of 5 mA cm-2. We obtain porosities below 30% by using substrate resistivities in the 0.0150.030 Ω cm range, etching current densities below 2.5 mA cm-2 and an electrolyte concentration of HF 50 wt%.
AB - We investigate sintering and reorganization of electrochemically etched mesoporous Ge layers. Sintering in nitrogen, forming gas, or argon atmospheres always yields a reorganized and oxidized porous layer. Water-insoluble Ge native oxides produced during etching do not hinder thermal reorganization, but evolve to water soluble oxides during annealing. Reorganized porous layers hence dissolve in subsequent water or HF dips. Sintering in hydrogen atmospheres removes native Ge oxides and prevents oxidation of porous layers. Porous layers with porosities less than 30% exhibit a compact closed surface after sintering, whereas porous layers with porosities exceeding 50% collapse. The porosity decreases linearly in a range of 57%45% for electrolyte concentrations and in a range of 3550 wt% for a specific resistivity of 0.013 Ω cm and an etching current density of 5 mA cm-2. We obtain porosities below 30% by using substrate resistivities in the 0.0150.030 Ω cm range, etching current densities below 2.5 mA cm-2 and an electrolyte concentration of HF 50 wt%.
KW - Lift-off
KW - Porous germanium
KW - Sintering
UR - http://www.scopus.com/inward/record.url?scp=78149361324&partnerID=8YFLogxK
U2 - 10.1016/j.solmat.2010.04.042
DO - 10.1016/j.solmat.2010.04.042
M3 - Article
AN - SCOPUS:78149361324
VL - 95
SP - 292
EP - 295
JO - Solar Energy Materials and Solar Cells
JF - Solar Energy Materials and Solar Cells
SN - 0927-0248
IS - 1
ER -