Quantom dot nanomaterial could offer solar energy from windows
Researchers at the Los Alamos National Laboratory in New Mexico have found that quantum dot technology applied to glass has the potential to achieve efficient and low-cost window photovoltaic systems. Applied to windows by pouring a solution of quantum dots and PVP polymer, the technology currently has 1.9% overall conversion energy efficiency over a lifetime of up to 14 years. Although an efficiency of 6% is required for practical usage, researchers are optimistic that the technology will continue to develop.

Luminescent solar concentrators (LSCs) are envisioned to reduce the cost of solar electricity by decreasing the usage of more expensive photovoltaic (PV) materials and diminishing the complexity of multi-cell PV modules. The LSC concept can also enable unconventional solar-energy conversion devices such as PV windows that can be especially useful in highly populated urban areas. Here we demonstrate low-loss, large-area (up to about 90 × 30 cm2) LSCs fabricated from colloidal core/shell quantum dots (QDs) whose optical spectra are tailored so as to minimize self-absorption of waveguided radiation. For improved compatibility with a polymer matrix and enhanced stability, QDs are encapsulated into silica shells, which allows for maintaining high emission efficiencies (∼70% quantum yields) under four-month exposure to air and light, and heat treatments up to 200 ∘C. The QD/polymer composites are processed into devices using standard doctor-blade deposition onto commercial window glasses. The fabricated semi-transparent devices demonstrate internal quantum efficiencies of more than 10% for dimensions of tens of centimetres.