An understanding of the surface and interface states of the organic material and the underlying anode material is meaningful for organic light-emitting devices(OLEDs).The tris-(8-hydroxyquinoline) aluminum(Alq

3

)/indium-tin oxide(ITO) samples were fabricated with traditional vacuum deposition.The surface and interface electronic chemical states of the Alq

3

and the underlying ITO have been investigated by X-ray photoelectron spectroscopy(XPS).The analysis on XPS spectra of the surface of the Alq

3

/ITO structure shows that

in Alq

3

molecule

the binding energy(

E

b

) of Al atoms is 70.7eV and 75.1eV

corresponding to Al(0) and Al(Ⅲ)

respectively.The binding energy of C atoms is 285.8eV

286.3eV and 286.8eV

corresponding to C atoms of C-C groups

C-O and C-N bonds

respectively.The N1s main peak locates at 401.0eV

corresponding to N atoms of C-N=C bonds.O atoms mainly bond to H atoms

and the bonding energy is 532.8eV.The N and O atoms also interact with Al atoms through coordination bonds.In order to investigate the interface electronic states of the Alq

3

/ITO structure

the samples are sputtered by argon ions beam.The analysis on XPS spectra of the interface of the Alq

3

/ITO structure indicates that

as the sputtering time of argon ions beam increasing

Al2p

C1s and N1s peaks get weaker

which indicates the Alq

3

film becomes thinner and thinner and the concentrations of the Al

C and N atoms reduce with increasing sputtering time.The core-levels of Al2p

C1s

N1s

O1s

In3d

5/2

and Sn3d

5/2

spectra slightly shift towards lower binding energy when the sputtering time increasing

this may be caused by the effect of oxygen

indium and tin in ITO diffusing into Alq

3

layer and the argon ions beam with high energy.Besides these

with the sputtering time of argon ions beam increasing

the relative concentration of O atoms from ITO diffusing into Alq

3

increases

and the interaction of O atoms with In and Sn atoms gradually reduces

which results in the In

2

O

3

and SnO

2

turning into suboxides or metal states In and Sn

so that the binding energy of In and Sn atoms decreases.