Regensburg 2022 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
HL: Fachverband Halbleiterphysik
HL 28: Organic Semiconductors 1
HL 28.4: Talk
Thursday, September 8, 2022, 10:15–10:30, H34
Heterostructure photodiodes of PbS nanocrystals with different types of ligands — •Shaimaa Abdalbaqi1, Florian Grassl1, Alexander Hofmann1, Ahmed Mansour2, Aladin Ullrich1, Norbert Koch2, Andreas Opitz2, Marcus Scheele3, and Wolfgang Brütting1 — 1Institut für Physik, Universität Augsburg, Germany — 2Institut für Physik & IRIS Adlershof, Humboldt-Universität zu Berlin, Berlin, Germany — 3Institut für Physikalische und Theoretische Chemie, Universität Tübingen, Tübingen, Germany
The influence of the ligands in coupled organic-inorganic nanostructures (COINs) on the performance of optoelectronic devices is investigated. We fabricate photodiodes based on pentacene and PbS nanocrystals coupled to organic ligands like 1,2-ethanedithiol (EDT) and tetrabutylammonium iodide (TBAI) and a combination of both as a heterostructure. These ligands were first separately used to fabricate a single ligand-type of organic-inorganic device and later compared with a heterostructure of PbS-EDT and PbS-TBAI. To tune the optical energy gap of COINs to align with the triplet level of pentacene, it was necessary to choose the suitable particle size. For this purpose, ultraviolet photo-emission spectroscopy (UPS) was used to determine the energy of the highest occupied molecular orbital (HOMO) and the work function of COINs. Devices with heterostructure COINs achieve a higher short circuit current than COINs with a single type of ligands. Incident photon to current efficiency (IPCE) shows different excitonic absorption peaks in the visible range for different stacks.