Higher index for cooler dots

My group at Boise State University focused on creating the best quantum dots on surfaces that were harder to grow on, more sensitive, and relatively unexplored. My two colleagues managed to get wonderful results from their work: using indium phosphide (InP) substrates, growing a couple of buffer layers they managed to get several systems to form quantum dots. Some emitted light, some didn't, but we learned from all of them!
1. The type of arsenic used changed where the triangles pointed!
https://iopscience.iop.org/article/10.1088/1361-6641/aba6e0/meta
2. Germanium (Ge) with a direct band gap?!
https://www.sciencedirect.com/science/article/pii/S0022024819306839
3. How do GaAs and Ge quantum dots compare?
https://pubs.acs.org/doi/abs/10.1021/acs.cgd.0c01528

Among other wonderful papers where I did not contribute!