UNSW researchers claim new solar efficiency record

The researchers from UNSW’s Photovoltaics Technology Transfer team, working with solar technology firm Centrotherm, claim to have achieved a new world benchmark of 19.3% efficiency in May for a mass-produced, crystalline silicon solar cell. They improved that result in June to advance the record to 19.4%. The researchers claim this will make solar power more affordable. The previous record for cells created with this process was 18.9%.

The new cells compare favourably with the 18% efficient cells commonly used in rooftop solar panels. The records were achieved without exotic materials or equipment, said Dr Matt Edwards, Program Manager of the Photovoltaics Technology Transfer team in the UNSW School of Photovoltaic and Renewable Energy Engineering. Dr Edwards said the exciting aspect of these records is that the researchers achieved these results in a short time, using an industry-standard silicon wafer and modified industry-standard equipment.

"It’s another step closer to solar power costing the same as coal-fired electricity." Dr Edwards said the gains, achieved on a standard p-type CZ silicon wafer had produced a low-cost cell which delivered "the best bang for your buck" of any mass-produced cell in the world. The record-breaking cells were produced using UNSW’s patented Laser Doped Selective Emitter (LDSE) process, which uses a high-powered laser and a light-induced plating process to create ultra-fine metal contacts on the cell surface, leaving more area exposed to light to create more power.

One of the advantages of LDSE technology is its ability to boost cell efficiency with simple modifications to existing screen-printed solar cell production lines - the most common mass-production systems in use today. The process is already in pilot production at some facilities. Dr Edwards said the group was now working on a new technology, double-sided LDSE (D-LDSE), which optimises both the front and rear surfaces of a solar cell to deliver efficiencies of up to 22%. The new 19.4% efficiency record was verified by the Fraunhofer ISE Solar Cell Calibration Laboratory and a paper detailing the work will be published in the inaugural edition of the Journal of Photovoltaics.