Researchers from Indian Institute of Technology Bombay, Mumbai have observed a new phenomenon in a semiconductor quantum dot-- particles of nanometre (a billionth of a meter) size which are also called artificial atoms) made of Cu₂ZnSnS₄  (CZTS). By shining Ultra Violet (UV) light, on the quantum dots immersed in an electrolyte, they noticed an increase in its capacitance. The effect could be engineered to serve as photocapacitors- capacitors that are charged using light.