Doctor-blade deposition of quantum dots onto standard window glass for low-loss large-area luminescent solar concentrators

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 x 30 cm(2)) 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 (similar to 70% quantum yields) under four-month exposure to air and light, and heat treatments up to 200 degrees 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.