Angle-dependent carrier injection in copper phthalocyanine thin films

摘要

We present that the carrier concentration injected from a silicon substrate to a copper phthalocyanine thin film depends on the incidence angle of photoexciting beam. At higher incidence angles of photoexciting beam, the modulation efficiency of terahertz transmission due to TM-polarized excitation is distinctly higher than one due to TE-polarized excitation. We find that this phenomenon is due to the enhancement of carrier injection which is expected when the incident light is more transmitted through the organic thin film.