LOS ALAMOS, NEW MEXICO — Researchers at the Los Alamos National Laboratory in New Mexico have developed a film of quantum dots that can turn windows into photovoltaic systems. <br /> <br />Quantum dots can be used as semiconductors. According to IEEE Spectrum, they consist of a CdSe inner core, a Cd1−xZnxS outer shell and a silica coating that prevents them from oxidation. The quantum dots are spead into a thin sheet that can be placed onto a glass window pane. <br /> <br />When photons from sunlight hit a quantum dot, it sends the electron in the valence band into the conduction band, leaving a hole behind. When the electron recombines with the hole in the valence band, a new photon with lower energy is generated. <br /> <br />This new photon propagates within the glass via internal reflections. Energy is then generated when the propagating photons reach the window frame, where solar cells are stored. <br /> <br />The coating of quantum dots can be used on any window and to turn it into a sunlight harvesters at costs lower than are currently available. <br /> <br />The study was published in Nature Energy on Oct 10.
