Sebastian Schoell

Year: 2013




Heterostructures of wide bandgap semiconductors such as silicon carbide (SiC) or group-III nitrides are attracting increasing interest for applications in the field of chemical and biological sensing. These biocompatible materials are particularly promising due to the possibility of bandgap engineering using the different SiC polytypes or AlxGa1-xN alloys, which could allow to optimize the charge transfer between the semiconductor device and the functional layer. A basic requirement for semiconductor biosensors based on organic-semiconductor hybrid structures is the direct covalent attachment of functional organic layers to the semiconductor surface. In my Ph.D. thesis, I systematically study different routes to obtain such functional layers on SiC and AlGaN alloys, including the silanization and hydrosilylation processes.
As an example, the figure shows a schematic view of the wet-chemical silanization process with either octadecytrimethoxysilane (ODTMS) or aminopropyldiethoxymethylsilane (APDEMS). We find that ODTMS layers on SiC exhibit very good diode-like electrical behavior but hinder the attachment of more complex molecules due to their chemically inert methly end-groups. Therefore, amino-terminated APDEMS layers were used e.g. for the immobilization of fluorescence-labeled proteins via an intermediate crosslinking step. To reveal the successful attachment of the proteins in fluorescence microscopy, such layers can be micropatterned as also shown in the figure.

In contrast to silanization, the hydrosilylation process of alkenes was supposed to require initially H-terminated surfaces. However, we are able to attach alkene molecules also to hydroxylated substrates via an addition reaction and have recently demonstrated this by the immobilization of fluorescent labeled proteins to TFAAD-layers on hydroxylated SiC and GaN surfaces. 

I greatfully acknowledge a Ph.D. fellowship from Universität Bayern e.V. and support by the CompInt graduate school.




Organic Functionalization of 3C-SiC Surfaces

ACS Appl. Mater. Interfaces, 5 (4), pp 1393–1399 (2013)

S. Schoell | M. Sachsenhauser | A. Oliveros | J. Howgate | M. Stutzmann | M. S. Brandt | C. Frewin | S. Saddow | I. D. Sharp

Online Reference

In vitro bio-functionality of gallium nitride sensors for radiation biophysics

Biochemical and Biophysical Research Communications 424 2 348-353 (2012)

M. Hofstetter | J. Howgate | M. Schmid | S. Schoell | M. Sachsenhauser | D. Adigüzel | M. Stutzmann | I. D. Sharp | S. Thalhammer

Online Reference

Surface functionalization of 6H-SiC using organophosphonate monolayers

Applied Physics Letters 100, 101601 (2012)

M. Auernhammer | S. Schoell | M. Sachsenhauser | K. C. Liao | J. Schwartz | I. D. Sharp | A. Cattani-Scholz

Online Reference

Ultrahigh gain AlGaN/GaN high energy radiation detectors

Physica Status Solidi (a) Applications and Materials Science 209 8 1562-1567 (2012)

Article Featured on Front Cover

J. Howgate | M. Hofstetter | S. Schoell | M. Schmid | S. Schäfer | I. Zizak | V. Hable | C. Greubel | G. Dollinger | S. Thalhammer | M. Stutzmann | I. D. Sharp

Online Reference

Electrical passivation and chemical functionalization of SiC surfaces by chlorine termination

Applied Physics Letters 98, 182106 (2011)

S. Schoell | J. Howgate | M. Hoeb | M. Auernhammer | J. A. Garrido | M. Stutzmann | I. D. Sharp

Online Reference

Thermally induced alkylation of diamond

LANGMUIR 26, 18862 (2010).

M. Hoeb | M. Auernhammer | S. Schoell | M. S. Brandt | J. A. Garrido | M. Stutzmann | I. D. Sharp

Online Reference

Photocatalytic Cleavage of Self-Assembled Organic Monolayers by UV-Induced Charge Transfer from GaN Substrates

Advanced Materials 22, 2632 (2010)

J. Howgate | S. Schoell | M. Hoeb | W. Steins | B. Baur | S. Hertrich | B. Nickel | I. D. Sharp | M. Stutzmann | M. Eickhoff

Online Reference

Electronic properties of self-assembled alkyl monolayers on Ge surfaces


I. D. Sharp | S. Schoell | M. Hoeb | M. S. Brandt | M. Stutzmann

Online Reference

Functionalization of 6H-SiC surfaces with organosilanes

APPLIED PHYSICS LETTERS 92 15 153301 (2008)

S. J. Schoell | M. Hoeb | I. D. Sharp | W. Steins | M. Eickhoff | M. Stutzmann | M. S. Brandt

Online Reference

TUM Technische Universität München TUM Technische Universität München Physik Department Elektrotechnik und Informationstechnik TUM Technische Universität München

Events & News

17 Jan 2018

ERC Consolidator Grant for Gregor Koblmüller   more

10 Aug 2017

Best Poster Awards for Ganpath Veerabathran and Alexander Andrejew at iNOW 2017   more

27 Jun 2017

Best Poster Award at Nanowire Week for Jochen Bissinger   more

15 Mar 2017

Dr. Kai Müller admitted to the “Junges Kolleg” of the Bavarian Academy of Sciences   more

27 Feb 2017

Two-photon pulses from a single two-level system   more


January 26, 2018

Reliability of hexagonal boron nitride dielectric stacks for CMOS applications   more

January 23, 2018

Helical states, spin-orbit coupling, and phase-coherent transport in InAs nanowires   more

January 16, 2018

New insights into novel (and conventional) materials using polarization-sensitive infrared magneto-spectroscopy   more