Transparent Conductive Oxide

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.

Potential Applications

• 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

For more information about the inventor(s) and their research, please see:

Dr. Stanislau Herasimenka's directory webpage