Photoinduced electrification of solids. III. Temperature dependences

TL;DR

This study investigates the temperature dependence of photoinduced voltages on solid surfaces, including high-Tc superconductors, to better understand the mechanisms behind photovoltage generation under illumination.

Contribution

It provides new experimental data on temperature effects in photoinduced electrification, especially in high-Tc superconductors, expanding understanding of the underlying processes.

Findings

Photovoltages vary with temperature across different materials.

Photodetachment of ions influences surface charge under illumination.

Temperature dependence offers insights into electrification mechanisms.

Abstract

Two preceding parts of a paper (cond-mat/0508457, cond-mat/0508460) considered the heuristic values of recent experiments pointing to the nearly universal occurrence of photovoltages across solid surfaces under short-circuit conditions. These voltages arise by virtue of a variety of spectrally-dependent mechanisms activated by incident photons. For the visible range, the photovoltages are obliged to the photodetachment of ions which leave the surface charged. In an attempt to learn more, we now study short-circuit photovoltages in well-defined materials including high-Tc superconductors within a broad temperature range down to liquid nitrogen. We believe our data provide a new insight into the process.