Dresden 2017 – wissenschaftliches Programm
CPP 64.3: Vortrag
Freitag, 24. März 2017, 10:00–10:15, CHE 91
Energy Level Control at ZnO/Organic Semiconductor Interfaces — •Raphael Schlesinger1, Sylke Blumstengel1, Stefanie Winkler2, Johannes Frisch1, Jens Niederhausen1, Ruslan Ovsyannikov2, Antje Vollmer2, Fritz Henneberger1, and Norbert Koch1,2 — 1Humboldt-Universität zu Berlin, Institut für Physik — 2Helmholtz-Zentrum Berlin - BESSY II
Hybrid inorganic organic systems (HIOS) are promising candidates for future (opto-)electronic devices by taking advantage of the complementary beneficial properties of two different material classes. However, inadequate interfacial energy level alignment is an intrinsic obstacle to superior device function. Hence, to design efficient HIOS devices, understanding and controlling HIOS energy level alignment is a key factor.
In this contribution we employ molecular electron donor or acceptor interlayers to tune the work function (φ) of ZnO between 2.2 eV (by using the organometallic donor [RuCp*mes]2) and 6.4 eV (by using F4TCNQ). Only for molecular acceptor adsorption, significant adsorption induced upward band bending of up to 0.9 eV is found within ZnO. Exploiting the huge φ modifications of ZnO, up- and downward HIOS energy level readjustments are shown, which realize ultimately low electron- or hole-injection barriers. Moreover, by using an OSC whose gap matches that of ZnO, the energy level offsets at the HIOS interface could be eliminated. This enables highly efficient, non-quenched energy transfer across the HIOS interface, which is usually inhibited by unfavorable energy level alignment.