The band gap of uranium dioxide is comparable to those of silicon and gallium arsenide, near the optimum for efficiency vs band gap curve for absorption of solar radiation, suggesting its possible use for very efficient solar cells based on Schottky diode structure; it also absorbs at five different wavelengths, including infrared, further enhancing its efficiency. Its intrinsic conductivity at room temperature is about the same as of single crystal silicon.
The dielectric constant of uranium dioxide is about 22, which is almost twice as high as of silicon (11.2) and GaAs (14.1). This is an advantage over Si and GaAs in the construction of integrated circuits, as it may allow higher density integration with higher breakdown voltages and with lower susceptibility to the CMOS tunnelling breakdown.
The Seebeck coefficient of uranium dioxide at room temperature is about 750 µV/K, a value significantly higher than the 270 µV/K of thallium tin telluride (TlSnTe) and thallium germanium telluride (TlGeTe) and of bismuth-tellurium alloys, other materials promising for thermoelectric power generation applications and Peltier elements.
The radioactive decay impact of the U and U on its semiconducting properties was not measured . Due to the slow decay rate of these isotopes, it should not meaningfully influence the properties of uranium dioxide solar cells and thermoelectric devices, but it may become an important factor for VLSI chips. Use of depleted uranium oxide is necessary for this reason. The capture of alpha particles emitted during radioactive decay as helium atoms in the crystal lattice may also cause gradual long-term changes in its properties.
The stoichiometry of the material dramatically influences its electrical properties. For example, the electrical conductivity of UO is orders of magnitude lower at higher temperatures than the conductivity of UO.
Uranium dioxide, like UO, is a ceramic material capable of withstanding high temperatures (about 2300 °C, in comparison with at most 200 °C for silicon or GaAs), making it suitable for high-temperature applications like thermophotovoltaic devices.
Uranium dioxide is also resistant to radiation damage, making it useful for rad-hard devices for special military and aerospace applications.
A Schottky diode of UO and a p-n-p transistor of UO were successfully manufactured in a laboratory.