Silicon solar cell with undoped tin oxide transparent electrode

Silicon heterojunction (SHJ) solar cells are one of the most promising directions in the future photovoltaic industry. The limited supply of rare indium and the high cost of silver paste are among the most important problems that SHJ solar cells will face. To overcome the obstacle of indium-based transparent electrodes for efficient SHJ solar cells, here we successfully prepared cheap and mass-producible undoped tin oxide (SnO x ) electrode materials by sputtering at room temperature. Taking advantage of its natural oxygen vacancy defect, the carrier mobility and resistivity of prepared materials reached 22 cm 2 V −1 s −1 and 2.38 × 10 −3 Ω cm, respectively. The SHJ solar cell with an undoped SnO x front transparent electrode demonstrated an efficiency of 24.91%. Furthermore, SnO x films have excellent chemical stability and can withstand corrosion by acid and alkali solutions during electroplating processes. Finally, SHJ solar cells with plating copper electrode and double-sided indium-based transparent electrodes halved were prepared, and a certified efficiency of 25.94% (total area of 274.4 cm 2 ) was achieved. Reducing critical materials such as indium and silver is of high importance for photovoltaics. Yu et al. demonstrate a certified 25.94% efficiency silicon heterojunction solar cell replacing part of indium-based electrodes with undoped tin oxide and using copper for contacts.