V Laboratory
Department of Physics
Nagoya University
Furocho, Chikusa, Nagoya

Photo-Seebeck effect in PbO

Renewable energy sources, such as solar light and abundant waste heat, have a potential importance to achieve a sustainable society. Recently, we have investigated a possibility of novel energy-conversion technique that utilizes solar light and waste heat simultaneously, which can be called as "photo-thermoelectrics".
Here we have grown large single crystals of PbO with a band-gap energy on the visible light region, and measured the transport properties under illumination. The photo-induced carriers contribute to the transport phenomena, and consequently the electrical conductivity increases and the Seebeck coefficient decreases with increasing photon flux density. The photo-induced carrier concentration estimated from the Seebeck coefficient increases almost-linearly with increasing photon flux density, showing a successful photo-doping effect on the thermoelectric property. On the other hand, the mobility also changes with illumination but the variation rate strongly depends on the illuminated photon energy, indicating a wavelength-selective photo-thermoelectrics to achieve high conversion efficiency.

"Photo-Seebeck effect in tetragonal PbO single crystals"
by Partha Sarathi Mondal, Ryuji Okazaki, Hiroki Taniguchi, Ichiro Terasaki
J. Appl. Phys. 114 (2013) 173710.

(Figure) Photon-energy-dependent photo-Seebeck effect in PbO.