Towards better solar cells: Exploring an anomalous phenomenon of electricity generation

Phys.org  October 22, 2024
The photovoltaic effect can occur without metal/semiconductor or semiconductor/semiconductor interfaces in materials with spontaneous electric polarization due to a lack of spatial inversion symmetry known as bulk photovoltaic (BPV) effect which facilitates photoelectric conversion. Researchers in Japan reported an experimental demonstration of the BPV effect in α-In2Se3 films along the out-of-plane direction by using graphite films as transparent electrodes. A short-circuit current was detected under white light irradiation, and the sign was inverted upon inverting the direction of electric polarization, thus suggesting its origin to be the shift current, distinct from the effect occurring at the interface. The quantum efficiency of photoelectric conversion for α-In2Se3 along the out-of-plane direction was a few orders of magnitude greater than that of conventional and layered ferroelectric materials. According to the researchers their results paved the way for the innovative design of photoelectric conversion devices… read more.  TECHNICAL ARTICLE