Self-assembled chalcopyrite ternary semiconductor CuBSe₂ nanocrystals: Solvothermal synthesis and characterisation

Chalcopyrites are important contenders among thin-film solar cells due to their direct band gap and higher absorption coefficient. Copper-boron-selenium (CuBSe₂) is a chalcopyrite material with a near-optimum band gap of ∼3.13 eV. Semiconductor CuBSe₂ nanorods were successfully prepared via a relatively simple and convenient solvothermal route. The device parameters for a single junction CuBSe₂ solar cell under AM 1.5 G are as follows: open circuit voltage of 310 mV, short-circuit current of 25.5 mA cm^-2, fill factor of 24%, and a power conversion efficiency of 1.89%. Based on a series of comparative experiments under various reaction conditions, the probable formation mechanism of crystals CuBSe₂ nanorods is proposed.