  The electronic properties of co-evaporated mixtures (blends) of manganese
phthalocyanine and the fullerene C$_{60}$ (MnPc:C$_{60}$) have been studied as
a function of the concentration of the two constituents using two supplementary
electron spectroscopic methods, photoemission spectroscopy (PES) as well as
electron energy-loss spectroscopy (EELS) in transmission. Our PES measurements
provide a detailed picture of the electronic structure measured with different
excitation energies as well as different mixing ratios between MnPc and
C$_{60}$. Besides a relative energy shift, the occupied electronic states of
the two materials remain essentially unchanged. The observed energy level
alignment is different compared to that of the related CuPc:C$_{60}$ bulk
heterojunction. Moreover, the results from our EELS investigations show that
despite of the rather small interface interaction the MnPc related electronic
excitation spectrum changes significantly by admixing C$_{60}$ to MnPc thin
films.
