Quantum Dots Boost Solar Cells
“Our particular 2-D material system (SnS2) [tin disulfide] is similar to Si [silicon], in that it has an indirect band gap, not providing sufficient electroluminescence for light-emitting diodes, but there are other 2-D materials with high luminescence such as MoS2 [molybdenum sulfide] WS2 [tungsten disulfide] which can be used in view of the Qdot-2D hybrid architectures for LEDs,” Mircea Cotlet, the physical chemist who led this work at Brookhaven Lab’s Center for Functional Nanomaterials (CFN ), a Department of Energy (DoE) Office of Science User Facility, told EE Times in an exclusive interview.
Instead of emitters, Brookhaven concentrated on receivers of optical energy in layered metal dichalcogenide semiconductors—dual chalcogen anions (ions with more electrons than protons) plus one or more electropositive elements usually sulfides, selenides, and tellurides, rather than oxides—in Brookhaven’s case sulfide). Brookhaven did the work with Stony Brook University (including doctoral candidate Prahlad Routh) and the University of Nebraska.
The researchers call their material a hybrid because they dope the electrical conductivity of layered tin disulfide semiconductor with the light harvesting of different spectrums of light from various sized quantum dots. In more detail, the quantum dots absorb the frequency of light corresponding to its diameter, then transfer their energy to the tin disulfide semiconductor. As a result, they prove to be a good candidate for solar light conversion and other similar light sensors.
For more detail: Quantum Dots Boost Solar Cells