ZnO Based and Organic/Hybrid Nanostructures

Structural, Optical, and Electrical Characterization of Functional Hybrid Nanostructures

Zink oxide (ZnO) nanowires provide unique properties as are optical transparency in the visible range, chemical stability, simple synthesis processes resulting in cheap production costs, as well as biological compatibility, and allow for large-scale applications. Therefore, they are used as nanoscale building blocks or modules for optoelectronic applications.  An increasingly interesting approach is the integration of ZnO-based nanocomposites with other organic or inorganic semiconductor materials making use of the different specific properties of the thus combined materials for the production of optoelectronic devices.

Due to the large surface-to-volume ratio in nanowires, their optical and electronic properties can be easily influenced and tailored by surface functionalization. By using electron microscopy (SEM and TEM) one can study the surface-to-volume ratio, the material density, the crystal structure as well as the surfaces of pure and functionalized ZnO and related nanostructures. For efficient optoelectronic devices, the whole structures including their internal, often hybrid interfaces must be of high crystalline or organic-material quality and posses a low density of impurities.

Since many years, the former group of Prof. Gutowski conducted research in this area, in the framework of numerous collaborations and especially of the DFG Research Group FOR 1616 Nanowire Electronics running from 2012 to 2019, see https://gepris.dfg.de/gepris/projekt/186128001.

Within these activities, sophisticated investigations of structural, optical, and electronic properties of ZnO based nanowire/quantum dot and hybrid organic/anorganic heterostructures involving mostly ZnO have been investigated.

Organic and Hybrid Transistors and Solar Cells

Since his retirement in 2021, Prof. Gutowski focuses his research on topics in the framework of the Bremen-Mexican network BREMEX (https://www.bremex-steaps.net/)  which he is the co-inventor of, including the General Agreement of the Univ. of Bremen with the largest Mexican University Universidad Nacional Autonomá de México (UNAM).The focus is on hybrid (anorganic side ZnO or related materials based) and pure organic semiconductor devices comprising transistors and integrated devices etc. for the detection of environmental pollution, and concepts of novel solar cells. This is done in strong cooperation with the International Laboratory for Environmental Electronic Devices and Climate Center at ENES Morelia UNAM, Ass.Prof. Alejandra Castro Carranza, see (https://sites.google.com/enesmorelia.unam.mx/laidea-unam/home), and the Micro- and Nanotechnology Research Centre MICRONA, Veracruz University, Mexico (Prof. Jairo Nolasco).

Hybrid and Organic Semiconductor Nanostructures: Keywords of Research Aspects

  • Waveguides and gain dynamics in nanowires
  • Synthesis of nanowires (VLS - vapor-liquid-solid method and chemical synthesis)
  • Functionalized surfaces of nanowires (e.g., functionalization by colloidal quantum dots, polymers, metallic nanoparticles)
  • Nanowire/polymer heterostructures for LEDs and Solar Cells
  • Surface properties and photoluminescence characterisation of nanowires and hybrid structures
  • Hybrid and organic devices for environmental pollution detection
  • Electronic and optoelectronic properties of organic and hybrid solar cells