Publications by authors named "W J Nemeth"
Article Synopsis
- Effective surface passivation of monocrystalline silicon (c-Si) solar cells is essential for identifying and reducing bulk defects to improve efficiency.
- The study introduces Nafion, an organic copolymer, as a room-temperature passivation method for Czochralski (Cz) Si wafers, tested alongside traditional methods like AlO and liquid HF/HCl.
- Results indicate that Nafion offers similar or superior passivation effects at room temperature, maintaining quality for about 24 hours, making it a viable alternative for investigating bulk defects in c-Si solar technology.
Article Synopsis
- High-efficiency silicon solar cells utilize passivating contact structures to minimize recombination losses at the silicon surface and metal interface.
- One effective structure involves depositing heavily doped polycrystalline silicon on a silicon dioxide (SiO) layer, which can vary in thickness affecting how charge carriers move through it (either by tunneling or through pinholes).
- The study employs electron-beam-induced current imaging to explore the relationship between SiO layer properties and surface morphology, revealing that the formation of pinholes depends on the annealing conditions, allowing for potential control over these disruptions to enhance solar cell efficiency.
Article Synopsis
- High-efficiency crystalline silicon solar cells need textured surfaces to effectively trap light, but passivating these surfaces to minimize carrier recombination is challenging.
- Research focuses on how the structure of the textured Si surface affects the properties of the passivated contacts with polycrystalline silicon and a thin SiO layer.
- Findings reveal that the roughness of the textured surface creates a nonuniform SiO layer, which degrades contact passivation and leads to resistance issues, although effective solar cell efficiencies over 21% are achieved without transparent conductive oxide layers.
We have measured the thermal conductivity of amorphous and nanocrystalline silicon films with varying crystalline content from 85 K to room temperature. The films were prepared by the hot-wire chemical-vapor deposition, where the crystalline volume fraction is determined by the hydrogen (H) dilution ratio to the processing silane gas (SiH), R = H/SiH. We varied R from 1 to 10, where the films transform from amorphous for R < 3 to mostly nanocrystalline for larger R.
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