Summary of Quantum Dots Boost Solar Cells
This article details a Brookhaven National Laboratory project developing hybrid quantum dot and 2-D material systems to enhance optical energy absorption in devices like photovoltaics and sensors. The research focuses on layered metal dichalcogenide semiconductors, specifically tin disulfide (SnS2), to improve performance where traditional light emitters fail.
Parts used in the Quantum Dot-2D Hybrid System:
- Quantum dots
- Tin disulfide (SnS2)
- Silicon (Si)
- Molybdenum sulfide (MoS2)
- Tungsten disulfide (WS2)
- Lithium sulfides
- Lithium selenides
- Lithium tellurides
LAKE WALES, Fla—Quantum dots are already being used commercially to boost the output and expand the color range of ultra-high-definition televisions, eliminating the need for the rare earth elements for which China as virtually cornered the market. Quantum dots, however, can also be used to absorb light to boost the output of photovoltaics, photocatalysts, light sensors, and other optoelectronic devices according to Brookhaven National Laboratory (Upton, N.Y.)
“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.
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- What are quantum dots currently used for commercially?
They are used to boost output and expand color ranges in ultra-high-definition televisions. - Can quantum dots absorb light to boost other devices?
Yes, they can be used to absorb light to boost photovoltaics, photocatalysts, and light sensors. - Which 2-D material system is similar to silicon?
The SnS2 [tin disulfide] system is similar to Si because it has an indirect band gap. - Why is SnS2 not ideal for light-emitting diodes?
It has an indirect band gap that does not provide sufficient electroluminescence for LEDs. - Which materials have high luminescence suitable for LEDs?
Materials such as MoS2 and WS2 can be used in Qdot-2D hybrid architectures for LEDs. - What type of elements are included in layered metal dichalcogenide semiconductors?
They include dual chalcogen anions plus one or more electropositive elements like sulfides, selenides, and tellurides.
