Annealing Effect on Photovoltages of Quartz Single Crystals

We investigate the photovoltaic effects of quartz single crystals annealed at high temperatures in ambient atmosphere. The open-circuit photovoltages and surface morphologies strongly depend on the heating treatments. When the annealing temperature increases from room temperature to 900°C, the rms roughness of quartz single crystal wafers increases from 0.207 to 1.011 nm. In addition, the photovoltages decrease from 1.994 μV at room temperature to 1.551 μV after treated at 500°C, and then increase up to 9.8 μV after annealed at 900°C. The inner mechanism of the present photovoltaic response and surface morphologies is discussed.