Self-assembled Ge-islands for photovoltaic applications
| Autor: | H. Kibbel, Hartmut Presting, Johannes Konle |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Photocurrent
Materials science Photoluminescence Silicon business.industry Open-circuit voltage chemistry.chemical_element Germanium Heterojunction Condensed Matter Physics Atomic and Molecular Physics and Optics Polymer solar cell Electronic Optical and Magnetic Materials chemistry Optoelectronics business Common emitter |
| Zdroj: | Physica E: Low-dimensional Systems and Nanostructures. 16:596-601 |
| ISSN: | 1386-9477 |
| Popis: | We have fabricated silicon solar cells with embedded germanium layers to form three-dimensional islands in the Stranski–Krastanov growth mode. The additional Ge-layers increase the infrared absorption in the base of the cell to achieve higher overall photocurrent and overcome the loss in open circuit voltage of the heterostructure. In an UHV-MBE chamber up to 75 layers of germanium, each about 8 monolayers thick, separated by Si-spacer layers (9– 16 nm ) were grown on each other using standard 10 Ω cm p-type Si-substrates. The density of islands in the layers was increased by the use of antimony as surfactant, thus densities >10 11 cm −2 were realized. The islands were covered by a 200 nm thick Si-layer (n-type) on top which is used as emitter of the cell. Photoluminescence measurements, AFM and TEM-microscopy were used to characterize the growth of Ge-islands under various growth conditions and post-thermal treatment. Photocurrent measurements exhibit a higher response of the fabricated solar cells in the infrared regime compared to standard Si-cells. |
| Databáze: | OpenAIRE |
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