Improvement in performance of tandem solar cell by applying buffer layer, back reflector and higher crystallinity of the microcrystalline Si active layer of bottom subcell
| Autor: | Jaehyun Cho, Jinjoo Park, Junsin Yi, Anh Huy Tuan Le, Duy Phong Pham, Jung Soo Kim, Shihyun Ahn, S.M. Iftiquar, Junhee Jung |
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| Rok vydání: | 2017 |
| Předmět: |
010302 applied physics
Materials science Tandem business.industry Metals and Alloys 02 engineering and technology Surfaces and Interfaces 021001 nanoscience & nanotechnology 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Active layer Amorphous solid Crystallinity Optics Microcrystalline 0103 physical sciences Materials Chemistry Optoelectronics 0210 nano-technology business Absorption (electromagnetic radiation) Layer (electronics) Current density |
| Zdroj: | Thin Solid Films. 639:56-63 |
| ISSN: | 0040-6090 |
| DOI: | 10.1016/j.tsf.2017.08.016 |
| Popis: | Tandem-structured amorphous Si solar cells can absorb a broader range of solar spectra than a single-junction device. In a tandem cell, usually a thicker bottom subcell becomes necessary to absorb the required number of photons from long-wavelength light to generate the desired current density. Alternatively, an optoelectronically improved active layer and light-trapping scheme can also be used with a thinner bottom subcell. In this respect, we investigated bottom subcell of tandem solar cells with microcrystalline Si active layer. Three of the primary parameters that were progressively varied for the bottom subcells were the crystalline volume fraction (X c ) of the active layer, buffer layer at the i/n interface, and back reflector (BR). Here, the buffer layer and higher X c are expected to improve respectively the electronic properties of the i/n interface and the active layer of the bottom subcell. Furthermore, a suitable BR can reflect the unabsorbed long-wavelength light back to the cell for further absorption; thereby raising its current density. We have observed that low-power deposition of the microcrystalline Si active layer (150 W), an 8 nm thick buffer layer at the i/n interface, and a zinc oxide BR layer gave best results in a tandem solar cell. An optimized tandem cell exhibited an open-circuit voltage, short-circuit current density, fill factor, and efficiency of 1.445 V, 12.32 mA/cm 2 , 71.56%, and 12.74%, respectively. |
| Databáze: | OpenAIRE |
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