4. Spectral shift for photovoltaics

4.1 The benefits of spectral shifting

Current solar cells do not optimally absorb the entire solar spectrum. However, a great deal of work has gone into constantly improving the spectral efficiency of solar cells, particularly with thin-film cells made up of different layers. Each semiconductor material absorbs at a defined bandgap energy. The CIGS absorber has a bandgap that depends on the amount of gallium included in the semiconductor. Indeed, the bandgap energy of the CIGS absorber can vary from 1.035 eV to 1.68 eV