Colloidal organic pigment semiconductor nanocrystals

Date

Jan 16, 2015

Time

1:00 PM - 2:00 PM

Speaker

Dr. Eric Daniel Glowacki

Affiliation

Johannes Kepler University, Linz

Language

en

Main Topic

Materialien

Other Topics

Materialien, Physik

Host

Ulrike Steere

Description

Organic pigments have been ubiquitous throughout history and are widely produced today industrially as colorants in everyday products as various as cosmetics and printing inks. Here we describe a way to process archetypical organic pigments into useful electronic nanostructured materials. Our methodology relies on a ligand-mediated synthesis, transforming commercial colored pigment powders into stable colloidal solutions of semiconductor nanocrystals, highly suitable for electronic device developments. Tuning of process conditions can yield nanocrystals with zero, one, two and three dimensional shapes, exhibiting a wide range of optical absorption and photoluminescence over spectral regions from the visible to the near infrared. The utility of such colloidal nanocrystals is demonstrated in photodetectors with a responsivity of 0.9 A/W, and humidity sensors operating over a dynamic range of 7 orders of magnitude and ~0.1s response. Both devices are fabricated by paint brushing or drop casting of these nanocrystals on paper substrates and outperform devices prepared from the same starting materials by vacuum deposition by several orders of magnitude. Properties can be further contolled through the use of smart functional ligands such as riboflavin (vitamin B2). Through the use of controlled ligand chemistry, semiconducting pigments with a range of photo- and electrocatalytic properties are also demonstrated. The semiconducting nanocrystals described here offer a cheap and nontoxic alternative to inorganic nanocrystals, as well as a new paradigm for obtaining organic semiconductor materials from low-cost and nontoxic commercial colorants.

Links

• Seminars at the IFW

Last modified: Jan 16, 2015, 9:03:42 AM