News


16th March 2020:

Jence and Nick developed new shells for InP QDs: composed out of ZnMgSe. Big collaboration with the group of Liberato Manna and fantastic electron microscopy from the group of Sara Bals. Read the paper here:

Developing Lattice Matched ZnMgSe Shells on InZnP Quantum Dots for Posphor Applications


15th January 2020:

Ryan published a new paper on making more efficient InP quantum-dot solar cells by infilling the structure with ZnO using Atomic Layer Deposition. Great collaboration with the group of Ruud van Ommen! Read the paper here:

Atomic Layer Deposition of ZnO on InP Quantum Dot Films for Charge Separation, Stabilization and Solar Cell Formation.


2nd of January 2020:

The (FC) Houtepen group - together with others from the Optoelectronic Materials section @ TU Delft - wishes you, your family and friends all the very best for 2020. Here you can see us (attempting to) ice skate during our Christmas group-outing!


30th of December 2019:

Many papers have been in progress and finally got accepted by the end of the year! 

Ward's paper on the influence of different shells on the electrochemical characteristics of CdSe-based QD films was accepted in Chemistry of Materials: Electrochemical modulation of the photophysics of surface-localized trap states in core/shell/shell quantum dot films

Solrun's paper on stabilizing charges in quantum dot films has been accepted in the Journal of Chemical Physics: Enhancing the stability of electron density in electrochemically doped ZnO films.

Gianluca's paper on tuning the band-alignment in multicomponent QD films has been accepted in the Journal of Physical Chemistry C: Engineering the band alignment in QD heterojunction films via ligand exchange.

Nick zincs he finally found the position of Zinc in In(Zn)P nanocrystals: Locating and controlling the Zn content in In(Zn)P quantum dots.


6th of August 2019:

KNCV Golden Master Award 2019 Nominatie #3 - Indy du Fossé

The Royal Dutch Academy of Science (KNCV) made a very nice promo movie about Indy's research as a master student.

You can check it out right here!


16h of July 2019:

Solrun has just published her second first-author paper on freezing electrons after electrochemically doping semiconductor films! She tested the approach on a range of materials, such as quantum dots, fullerene and conductive polymers. We are getting closer and closer to permanent electrochemical doping :)! Well done Solrun!

Link: On the Stability of Permanent Electrochemical Doping of Quantum Dot, Fullerene, and Conductive Polymer Films in Frozen Electrolytes for Use in Semiconductor Devices


29th of May 2019:

PhD student Indy just published his first first-author paper! We studied the formation of defects at the surface of colloidal nanocrystals upon n-type doping (heavy metal!) with DFT. Yet another very fruitful collaboration with the group of Ivan Infante! Congratulations to everybody!

 

Link: The role of surface reduction in the formation of traps in n-doped II-VI  semiconductor nanocrystals: How to charge without reducing the surface


April 9th 2019:

PhD student Indy du Fosse was just selected as one of the three final candidates for the KNCV Golden master award 2019, a price for the best chemistry master thesis in the Netherlands. Congratulations Indy!


4th of April 2019:

Gianluca and Jaco's paper on the detection of holes in Cd-chalcogenide based QDs is accepted for publication in Nano Letters! These S-holes were well hidden for the past 20 years!

Link: Spectroscopic evidence for the contribution of holes to the bleach of Cd-chalcogenide quantum dots

 

 


13th December 2018:

Frank(y) and Gianluca's paper on some extensive modelling for Carrier Multiplication in quantum dots has been published in ACS Applied Energy Materials! 

Link: Model to determine a distinct rate constant for carrier multiplication from experiments


31 October 2018:

Ward's paper on "Tuning and Probing the Distribution of Cu+ and Cu2+ Trap States Responsible for Broadband Photoluminescence in CuInS2 Nanocrystals" was published today in ACS Nano, and is now available online.

Link: Tuning and Probing the Distribution of Cu+ and Cu2+ Trap States Responsible for Broadband Photoluminescence in CuInS2 Nanocrystals


30th October 2018:

 

Nick's paper "Finding and fixing traps in II-VI and III-V colloidal quantum dots: The importance of Z-type ligand passivation" was published today in Journal of the American Chemical Society, and is now available online.

Link: Finding and fixing traps in II-VI and III-V colloidal quantum dots: The importance of Z-type ligand passivation


23 October 2018:

Two papers from the group have been published today:

 

Ward and Indy wrote a paper titled "Spectroelectrochemical Signatures of Surface Trap Passivation on CdTe Nanocrystals", published today on Chemistry of Materials.

Link: Spectroelectrochemical Signatures of Surface Trap Passivation on CdTe Nanocrystals

 

 

Ryan's new paper on "Highly Photoconductive InP Quantum Dots Films and Solar Cells" was published today in ACS Applied Energy Materials, and is now available online.

Link: Highly Photoconductive InP Quantum Dots Films and Solar Cells


10 October 2018:

 

 

The review paper by Abiseka and Ryan on the development and perspectives of Quantum Dot solar cells was published today on Applied Sciences, and is now available online.

Link: Quantum Dot Solar Cells: Small Beginnings Have Large Impacts


31st August 2018:

We congratulate with Mark van den Brom for successfully defending his Master Thesis on "Engineering a type-II band alignment in CdSe-PbSe QD films".


 10th July 2018:

In the last two weeks many bachelor students have successfully defended their Bachelor thesis:

Marijn Koel - Exploring spectroelectrochemistry on 2-D cadmium selenide nanoplatelets.

Rianne Wessels - Photodoping of CdSe nanocrystals and charge stabilization in a polymer matrix.

Pieter van Uffelen - The Double Role of Shells

Christel Koopman - Improving charge stability of electrochemically doped semiconductors.

Amy van Leiden - Kinetic Monte Carlo simulations of carrier transport in InP QD films.

Laura Donk - Towards stable and permanent electrochemical doping of quantum dots

Huub Bergstein - Making CdTe-based photovoltaic devices and the effects of passivating salts.

Congratulations to all of you, and good luck for your future achievements!


5th July 2018:

Today Qianli Yu defended successfully her Master thesis on "Synthesis, surface passivation and characterization of ultrathin 2D PbS nanoplatelets". Congratulations!


 4th July 2018:

Congratulations to Abiseka Ganesan, for successfully defending his Master thesis on "Quantum dot solar cells and electrochemical doping of QD films".


13th June 2018:

Gianluca's paper "Hot-electron transfer in quantum-dot heterojunction films" was published in Nature Communications, and is now available online.

Link: Hot-electron transfer in quantum-dot heterojunction films


28th May 2018:

Ryan's paper "Selective antimony reduction initiating the nucleation and growth of InSb quantum dots" was published in Nanoscale and it's now available online.

Link: Selective antimony reduction initiating the nucleation and growth of InSb quantum dots


2nd May 2018:

 

 Solrun's paper "The Role of Dopant Ions on Charge Injection and Transport in Electrochemically Doped Quantum Dot Films" was published in JACS, and is now available online.

Link: pubs.acs.org/doi/full/10.1021/jacs.8b01347

 

 


17th April 2018:

Frank Spoor's paper "Asymmetric Optical Transitions Determine the Onset of Carrier Multiplication in Lead Chalcogenide Quantum Confined and Bulk Crystals" was published in ACS Nano, and is now available online.

Link: Asymmetric Optical Transitions Determine the Onset of Carrier Multiplication in Lead Chalcogenide Quantum Confined and Bulk Crystals

 

 


12th February 2018:

We give a warm welcome to many new students:

Marijn Koel - Exploring the spectroelectrochemistry of CdSe nanoplatelets and their core-shell and core-crown derivatives.

Rianne Wessels - Investigating the possibility to stabilize electrons in colloidal quantum dots by polymerization of the surrounding solvent, which could possible be used for continuous wave quantum dot lasers.

Pieter van Uffelen - Electrochemically injecting electrons into core/shell quantum dots with varying shell thickness, in order to investigate the lasing threshold of this interesting class of materials.

Christel Koopman - Improving the stability of electrochemically doped semiconductors.

Amy van Leiden - Extracting electron mobilities from spectral diffusion in Transient Absorption measurements.

Laura Donk - Electrochemical doping of quantum dots via photo-polymerization.


27th November 2017 - 1st December 2017:

Experiments at the ESRF (European Synchrotron Radiation Facility).

...and consequences thereof.


13th November 2017:

We would like to welcome Mark van den Brom as a new Masters student in the group. Mark will try to change the band-alignment between PbSe and CdSe QDs by varying their ligand passivation.


31st October 2017:

Arjan, Daniël Vanmaekelbergh (Utrecht University) and Liberato Manna (IIT Genova, TUDelft) in the chemistry lab.


October 10th 2017

The group's paper "Continuous-wave infrared optical gain and amplified spontaneous emission at ultralow threshold by colloidal HgTe quantum dots" was published by Nature Materials. 

This is the result of a long standing project with the group of Zeger Hens at Ghent University.

In this work we make use of trap states on the surface of HgTe quantum dots to engineer a system in which optical gain occurs virtually without excitation threshold. This allows amplified stimulated emission induced by Continuous Wave excitation at tunable infrared wavelengths, including the technologically relevant telecom wavelengths of 1.3 and 1.55 micrometer.


October 3rd 2017:

Congratulation to Julius Monchen, who has successfully defended his Bachelor Thesis, "Passivation of Surface Traps in Colloidal CdTe Nanocrystals". Julius will keep working in the group for the next few months, to extend his exciting results.


August 29th 2017:

Congratulation to Elise Groen, who has successfully defended her Bachelor Thesis, “In(Zn)P Quantum Dots for Utilisation in Solar Cells”.


August 25th 2017:

Ward's and Solrun's paper "Switching between Plasmonic and Fluorescent Copper Sulfide Nanocrystals" was published in JACS and it's now available online.

Link: pubs.acs.org/doi/abs/10.1021/jacs.7b07788


23rd August 2017:

We would like to welcome Qianli Yu as a new Masters student in the group. Qianli will try to increase the PL and QY of 2D PbS nanoplatelets by passivation, shell growth and or core-crown growth.


14th August 2017:

We would like to welcome Jence Mulder as a new Masters student in the group. Jence is working on the growth of inorganic shells around InP quantum dots to increase their photoluminescence properties for phosphor applications.


July 7th 2017:

Jorn Rietveld graduated on his Bachelor thesis "Chemical doping of PbSe quantum dots". This is very interesting work we will definitely continue with. Well done Jorn, and congratulations.


July 5th:

Max de Graaf graduated on his BSc thesis entitled "Investigation of the radiative recombination process in CuInS2 QD films by performing in-situ absorption and in-situ photoluminescence spectro-electrochemistry measurements".

According to Max, this is quite a catchy title. Nonetheless, he graduated with a grade 9! Congratulations


June 22nd 2017:

At the Applied Sciences science day Arjan received the teacher of the year award for the department of chemical engineering.



June 6th 2017:

Nick's and Francesca's paper  "Ga for Zn Cation Exchange Allows for Highly Luminescent and Photostavle InZnP-Based Quantum Dots" is now online at Chemistry of Materials. This is an open access paper.

Update: The paper was a Top download from the Chemistry of Materials website in June. If you click the link above many times, perhaps it can stay that way.