Figure 2. Resistivity and carrier concentration of Cu₂O films grown at different deposition temperatures in a fixed P(O₂) of 10 mTorr.

Inset of the figure shows the optical absorption coefficient as a function of photon energy (=hv) as in equation, αhv = (hv − E_g)^1/2. Here, h is Planck’s constant and v is the frequency of the incident photon. Single phase Cu₂O film grown at 750 °C was measured by a UV/V is spectrophotometer in a diffuse reflectance mode using an integrating sphere.