Ballistic Electron Emission Microscopy/Spectroscopy on Au/Titanylphthalocyanine/GaAs Heterostructures

Abstract

In this article Au/titanylphthalocyanine/GaAs diodes incorporating ultra smooth thin films of the archetypal organic semiconductor titanylphthalocyanine (TiOPc) were investigated by Ballistic Electron Emission Microscopy/Spectroscopy (BEEM/S). Analyzing the BEEM spectra, we find that the TiOPc increases the BEEM threshold voltage compared to reference Au/GaAs diodes. From BEEM images taken we conclude that our molecular beam epitaxial (MBE) grown samples show very homogeneous transmission, compared to wet chemically manufactured organic films. The barrier height measured on the Au-TiOPc-GaAs is Vb ~ 1.2eV, which is in good agreement with the data found in reference [1]. The results indicate that TiOPc functions as a ptype semiconductor, which is plausible since the measurements were carried out in air [2].

Ballistic electron attenuation length in titanylphthalocyanine films grown on GaAs

“…First measurements on the Au/TiOPc/GaAs heterostructure are published in [20] and the temperature dependence of the Schottky barrier height in Au/TiOPc/GaAs is already described in [21]. In this paper, we focus on the transmission behavior of hot electrons through TiOPc and calculate the corresponding electron attenuation length.…”