Photoemission spectroscopy was used to investigate the heterojunctions between InP(110) and two organic semiconductors, N,N′-diphenyl-N,N′-bis(1-naphthyl)-1-1′biphenyl-4,4″diamine (α-NPD) and copper-phthalocyanine (CuPc). Both interfaces exhibit dipole barriers that demonstrate the breakdown of the vacuum level alignment rule, and suggest a displacement of negative charge form the organic to the inorganic semiconductor. The direction of the charge displacement is consistent with the relative electron affinities and ionization energies of the solids.
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy