[ifuller]

I am trying to find the valence and conduction band energy levels of multiple elements and compounds. I have managed to find various band gap energies but am looking for the location of the bands themselves. Does anyone know where this data might be compiled? I am not even sure it has been.

For example I have found the necessary data for TiO2
Band Gap = 3.2eV
Valence Band is located at 3eV
Conduction Band is located at -0.2eV

Thank you in advance for any help.

[FreeTheBee]

If you have access to Nature you can check here,
Photoelectrochemical cells, Michael Grätzel, Nature 414, 338-344(15 November 2001)
doi:10.1038/35104607
I used to have some diagram with band positions of common semiconductors, but I cannot find it. If I do, I will post.

Maybe it helps to search for 'electron affinity' and 'flat band potential' of semiconductors as these are both related to the band positions. Note also that the position of the band edges depends on the environment of the semiconductor.

[chepec]

I have also experienced a certain lack of tabulated data on this subject in the literature. But I have found one article that does a good job tabulating absolute energy levels for quite a few semiconductors. But as always, beware of typos and always consider the effect the electrolyte pH has on the energy levels.

Yong Xu and Martin A. A. Schoonen. "The absolute energy positions of conduction and valence bands of selected semiconducting minerals."
American Mineralogist, Vol. 85, Issue 3-4, pages 543–556, 2000.
URL http://www.minsocam.org/MSA/AmMin/TOC/2000/MA00.html

[ifuller]

Thank you both! I will definitely look at those sources.

[Enthalpy]

For semiconductors at least, a good address:
http://www.ioffe.ru/SVA/NSM/Semicond/

Then, be wary that bandgaps are accurately known (at least for the materials where it matters, which are semiconductors), but electron affinities aren't at all: discrepancies of 1eV are common. Electron affinity is difficult to measure, as it requires ultra-clean surfaces that last for a short time even in ultra vacuum.

As well, electron affinity depends a lot on crystal orientation, even for metals.

I doubt the conduction band of TiO2 is 3eV ABOVE vacuum. It might have happened to be 3eV above some Fermi level when the measurement was made, but then the Fermi level fluctuates anywhere between both bands in an insulator or a semiconductor.

More: if you need them to compute a contact between different materials, be aware that the interface (contamination and so on) determines what happens, not the bulk properties of both materials. Any prediction based on band properties would be very false.

Well, in short: do not believe electron affinity nor absolute band position, they use to be very false.