Measuring Infrared Emission from InSb Quantum Dots
Abstract
Small bandgap semiconductors, such as PbS, PbSe, and InSb, that are optically sensitive to near- and mid-infrared (IR) light can be used to increase the wavelength solar spectrum sensitivity of modern, multipartite photovoltaics. As with other semiconducting materials, small bandgap semiconductors can be formed into quantum dots or colloidal nanocrystals, thus enhancing both their absorptive cross-sections and emission efficiencies, which are crucial optoelectronic parameters. Critically, the large exciton radii of many small bandgap semiconductors allows researchers to control the semiconducting bandgap by altering the quantum dot diameter around or below the exciton radius ( 10 to 20 nm). Here, we discuss the design and construction of a setup to detect mid-IR (1.5 to 6 mm) photoluminescence (PL) using a tunable, visible excitation source. Using this system, we measure PL from 15 nm-diameter InSb quantum dots produced using Sn-seeded growth and atomic layer deposition. We find that the PL from these quantum dots is centered between 2 to 3 mm confirming their high crystallinity and TEM-determined average ensemble diameter. In addition to these results, future measurements using high-intensity visible and near-IR excitation will be discussed.
University of Wyoming.- Publication:
-
APS April Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..APRG12006T