Amorphous nanostructures from AIMD

Semiconducting quantum dots (QDs) have a broad number of applications due to their unique size- and shape- dependent electronic and optical properties. When people use first-principles simulations to study structure-property relationships in QDs, the experimental bulk crystal structure is the most commonly used model. However, experiments show QDs may possess distinct, amorphous structures.
We have developed an approach to discover amorphous nanostructures using high-temperature ab initio molecular dynamics. In this work we choose indium phosphide (InP) as an example, but it can be applied to other amorphous materials, such as transition-metal phosphides. Starting from InP zigzag nanoribbon structures (a single layer of InP(111)), rearrangement into a stabilized, higher-coordinate but amorphous cluster is observed across a large size range. The clusters exhibit exponential decrease in energy per In atom and P atom pair with cluster size but small energy difference at each size in final amorphous structures even when starting from several different initial configurations. Interestingly, we find the amorphous clusters are lower in energy than geometry optimized spherical models of bulk structure typically used for simulations of quantum dots. In the low-energy sampled amorphous structures, some interesting configurations absent in bulk crystal structure are observed, such as high-coordinated indium and phosphorus with coordination numbers up to five and seven, and phosphorus-phosphorus dimers.

Be sure to check our recent publication!

About Us

The Kulik group focuses on the development and application of new electronic structure methods and atomistic simulations tools in the broad area of catalysis.

Our Interests

We are interested in transition metal chemistry, with applications from biological systems (i.e. enzymes) to nonbiological applications in surface science and molecular catalysis.

Our Focus

A key focus of our group is to understand mechanistic features of complex catalysts and to facilitate and develop tools for computationally driven design.

Contact Us

Questions or comments? Let us know! Contact Dr. Kulik: