High-efficiency tandem photovoltaic devices with quantum colloidal solar cells and photoactive materials of organic mass heterogjunction have been developed by a team of UNIST researchers led by Professor Sung-Yeon Jang.
The colloidal quantum solar cells (CQD) have soon attracted considerable attention in the field of photovoltaic energy because they are flexible and lightweight, easier to manufacture than conventional silicon solar cells and without loss of efficiency.
Quantum dots are nanoscopic-sized semiconductor particles. They have various useful and interesting characteristics, primarily an emission wavelength that depends on the size.
Basically, quantum points can absorb light in the near infrared, something that other cells and active photo layers cannot do.
Jang’s research team has developed a new photoactive quantum point technology that compensates for the loss of external quantum efficiency in the near infrared region. They also used an intermediate layer to achieve power conversion efficiency. These new tandem hybrid solar cells are made at room temperature and therefore their manufacture is cheaper than silicon solar cells.
“The hybrid tandem device has shown almost negligible degradation after storing air for three months,” says Jang himself.