Colloidal Semiconductor Quantum Shells for Solution-Processed Laser Applications

Quantum dots (QDs) are well known for their tunable emission properties, making them ideal for a variety of applications ranging from bioimaging to quantum computing. However, their application in lasing has historically been limited due to significant non-radiative losses at higher excitation powers, primarily caused by Auger recombination. This process converts energy into heat rather than light, reducing lasing efficiency. To address this, spherical quantum wells—termed Quantum Shells (QSs)—have been developed. The unique geometry of QSs promotes exciton-exciton repulsion, effectively reducing Auger recombination and improving multi-exciton quantum yield (QY). Larger quantum shell structures have been shown to offer higher multi-exciton QY and longer lifetimes. We present recent advancements demonstrating the use of QSs in various lasing applications, including optically pumped femtosecond lasers, quasi-continuous wave (quasi-CW) lasers, and two-photon "upconverted" lasers.