It has been reported that researchers from the esteemed Indian Institute of Technology (IIT) Bombay have used a top perovskite device with an efficiency of up to 17.1% and built a four-terminal (4T) silicon-perovskite solar cell. The top device has a near-infrared (NIR) transparent perovskite cell and the rear electrode comprises a room-temperature sputtered transparent conducting electrode. This enables more lighting to enter the bottom silicon device.

As per the research article, Stable and Efficient Large-Area 4T Si/perovskite Tandem Photovoltaics with Sputtered Transparent Contact, that was published on Solar RRL, the cell has outstanding stability in the dark, as well as continuous heating conditions. The development of the sputtered top transparent conducting electrode (TCE) layer and oxide buffer layer at room temperature (25 °C) leads to reproducible, highly efficient NIR-transparent PSCs of both small area (0.175 cm2) with power conversion efficiency (PCE) of 17.1% and large area (0.805 cm2) with PCE of 16.0%.

With an n–i–p structure and utilizing an anti-reflecting coating, the cell has an electron transport layer (ETL) made of tin(IV) oxide (SnO2), a perovskite layer, a molybdenum oxide (MoOx) layer, and a spiro-OMeTAD hole transport layer (HTL). Th MoOx buffer layer protects the perovskite photo-absorber and charge transport layers from any sputter damage.

The article emphasized that this development could open doors to enabling industry-compatible TCE-based low-cost Si/perovskite tandem photovoltaics, and also make way for its potential use in niche applications like building integrated photovoltaics.