Method for characterizing energy level of core/shell nanoparticle

A method for characterizing an energy level of a core/shell nanoparticle including a core and a shell surrounding the core, the method comprising:

• measuring a core-level binding energy EBCore(core-level) and a valence band maximum energy EVBM(core) of a core in a core nanoparticle having only the core using photoelectron spectroscopy;
• measuring a core-level binding energy EBCore-Shell(core-level) of the core in the core/shell nanoparticle and a valence band maximum energy EVBM(shell) of the shell in the core/shell nanoparticle using photoelectron spectroscopy;
• and
• calculating a valence band maximum energy E′VBM(core) of a material forming the core in the core/shell nanoparticle, wherein the valence band maximum energy E′VBM(core) of the material forming the core in the core/shell nanoparticle is given as follows:
• E
• VBM
• ′
• (
• core
• )
• =
• E
• VBM
• (
• core
• )
• +
• E
• B
• Core
• -
• Shell
• (
• core
• -
• level
• )
• -
• E
• B
• Core
• (
• core
• -
• level
• )
• .