Heterojunction silicon solar cells with undoped tin oxide transparent electrodes.

Silicon heterojunction (SHJ) solar cells: Relying on heterojunction between semiconductors with different energy bands, they are one of the most promising photovoltaic technologies. These cells have a long history of excellent power conversion efficiency and stability. However, their widespread application is constrained by rare and expensive materials and incompatibility with existing manufacturing processes.

In a groundbreaking study, scientists have proposed an innovative design and manufacturing strategy designed to reduce the production cost of SHJ's solar technology without compromising its efficiency. The findings, recently published in the journal Nature Energy, demonstrate the potential of solar cells fabricated using this new method.

The researchers successfully solved two key challenges, namely overcoming the limited supply of indium and the high cost of silver paste, and came up with a cost-effective and mass-produced solution. They successfully prepared an undoped tin oxide (SnOx) electrode material by room temperature sputtering. These transparent electrodes are a key component of SHJ solar cells and are manufactured using mass-production-ready deposition technology that is compatible with existing production processes. According to the preliminary test results, these materials show excellent performance, resulting in excellent solar cell performance.

The undoped SnOx electrode has a native oxygen vacancy defect and excellent carrier mobility and resistivity of 22 cm² V⁻¹ s⁻¹ and 2.38 × 10⁻³ Ω, respectively

cm。 The results showed that SHJ solar cells equipped with undoped SnOx pre-transparent electrodes achieved an excellent efficiency of 24.91%. In addition, SnOx films exhibit excellent chemical stability and are resistant to corrosion by acidic and alkaline solutions during the plating process. To further demonstrate the potential of this innovation, the researchers developed SHJ solar cells with electroplated copper electrodes and bifacial indium-based transparent electrodes, achieving a certified efficiency of 25.94% (total area 274.4 cm²).

This latest study highlights the potential of undoped SnOx as a viable alternative to the fabrication of transparent electrodes for SHJ solar cells, replacing indium and silver while maintaining high solar cell efficiency, significantly reducing production costs and complexity. This innovative approach has the potential to pave the way for the mass production and commercialization of SHJ's PV technology.