Scientists from Los Alamos National Laboratory recently assessed the status of research into colloidal quantum dot lasers with a focus on prospective electrically pumped devices, or laser diodes.
“Colloidal quantum dot lasers have tremendous potential in a range of applications, including integrated optical circuits, wearable technologies, lab-on-a-chip devices, and advanced medical imaging and diagnostics,” said Victor Klimov, a senior researcher in the Chemistry division at Los Alamos. “These solution-processed quantum dot laser diodes present unique challenges, which we’re making good progress in overcoming.”
Semiconductor lasers, or laser diodes, are an essential part of many common consumer products as well as sophisticated equipment used in telecommunication, scientific research, medicine, and space exploration. Usually, these devices employ ultrathin semiconductor films, or quantum wells, grown via vacuum-based layer-by-layer atomic deposition. While allowing for exquisite control of the material’s properties, this growth method is highly demanding and requires a clean-room environment. In addition, it is restricted to a fairly small number of mutually compatible materials used as a lasing medium and an underlying substrate. Specifically, compatibility issues greatly complicate integration of existing semiconductor lasers with standard silicon-based microelectronics.
“These problems can, in principle, be resolved with inexpensive solution-processable light emitters,” Klimov said. “In particular, an attractive alternative to standard quantum wells is semiconductor particles prepared via bench-top colloidal chemistry.”