Mechanism of pyrite photoconductance under an 808 nm-laser irradiation: a photo-thermal synergism

Abstract

Abstract As an earth-abundant mineral semiconductor, pyrite absorbs and converts photons under solar radiation to produce electrons, which is considered one of the important basic energy forms newly discovered in nature, and the response mechanism of light radiation on semiconductor minerals remains to be further explained. Here in this study, we focus on the photoconductance mechanism of natural pyrite, that is, an optical and electrical phenomenon in which the conductivity of a semi-coke is enhanced by absorption of an 808 nm wavelength laser. On the one hand, the photon energy of the 808 nm laser is higher than the band gap of pyrite, thus it can excite photogenerated charge carriers. On the other hand, the thermal effect produced by pyrite after absorbing the light energy will also improve the electrical conductivity. By monitoring the relationship between photoconductance, temperature, and time under laser irradiation, a photo-thermal synergism can be observed and evaluated. We aim to provide a basis for the study of the basic physical properties of natural pyrite, which will help to describe its role in geological and biological evolution.