Silicon heterojunction (SHJ) technology can provide high solar cell efficiency and low cost in high volume manufacturing. Transparent conductive oxides (TCOs), a component in SHJ cells, can help achieve good conductivity and electrical contact with metals for transferring current. However, optimizing TCO layers in SHJ solar cells requires a tradeoff between losses arising from optical, recombination, and series resistance effects. Therefore, there is a need to design an optimal SHJ configuration that minimizes losses in TCOs and maintains electrical properties.
Researchers at ASU have developed a new method to improve the optical response of SHJ cells by using ITO/SiOx:H stacks and developed a way to integrate the stacks with Cu plating. The technology comprises a SiOx:H film on the front of the cell to serve as a second antireflection (AR) coating to allow thinner TCOs that absorb less light. Meanwhile, hydrogen treatment from SiOx:H from post-deposition annealing maintains the conductivity of the thin TCO. At the rear side of the cell, a thin-ITO/SiOx:H/Ag film serves as a superior rear mirror compared to conventional films. Overall, the researchers developed a method to reduce optical losses in TCOs without compromising conductivity.
- Silicon heterojunction solar cells
- Transparent conductive oxides
- Thin-film optoelectronics
Benefits and Advantages
- Effective – The method uses front and back side films that give excellent front-side conductivity and superior rear-side reflection, attributing to a high efficiency
- Innovative – The design gives a way to incorporate the ITO/SiOx:H stacks with copper plating and using ITO/SiNx/SiOx triple layer AR coatings, leading to improved performance and reduced optical losses
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