Photo-Electrochemical Technologies for Energy Efficient Dynamic Windows

PV-Powered Electrochromic Devices

A technological platform for the fabrication of advanced photo-electrochemical devices is operating at the Dye Solar Labs of IIT-CBN. Its major research target refers to development of highly efficient electrodes made by transparent conductive nanoscrystals having finely controllable nano-architectures, whose peculiar prerogatives can be advantageously exploited in both electrochromic and energy storage devices.

The successful implementation of shape-tailored colloidal nanocrystals into these devices passes indeed through the realization of good quality mesoporous electrodes which must act as efficient electrochemical capacitors.

This research line is indeed conceived to address the most crucial issues associated with:

  • processing of colloidal nanomaterials
  • fabrication of high quality nanostructured electrodes (by screen-printing and ink-jet printing)
  • analysis of their fundamental optical and electrochemical features
  • design/realization of innovative device architectures

Scientific findings and technical achievements delivered in this framework will be capitalized in the development of a novel class of intelligent dual band electrochromic devices, which are capable of achieving independent control over the visible and near-infrared regions of the solar spectrum.

They will also integrate a set of suitable photovoltaic generators -properly designed and engineered to make the optical switching processes of the electrochromic device being responsively driven by solar light intensity- with no need for external powering.

Significant efforts in this framework are also devoted to design and optimization of dynamically tunable glazing elements prototypes to be feasibly and cost-effectively integrated into a building envelope.

Dynamic Plasmonic Windows

Reliable exploitation of the extraordinary optical prerogatives of electron oscillations at the interface between a doped semiconductor and a dielectric medium, which are commonly referred to as surface plasmons, is prospected to push the blooming of a new class of advanced dynamic windows offering a unique opportunity to selectively and reversibly control the intensity of incoming thermal radiation without affecting the window’s transparency.

Electrochemical injection of electrons into weakly doped transparent conductive nanocrystals induces a shift in the plasmon frequency and gives rise to the new functionality of selective optical modulation in the near-infrared region of the solar spectrum.

An accurate control and tuning of dopants as well as of the size and morphology of the nanocrystal allows determining the spectral response. Leveraging the plasmonic properties of chemically engineered semiconductor nanocrystals represents a new paradigm in this field, greatly expanding options for material selection to achieve targeted optical responses, and a likely successful strategy.

By controlling the solar heat gain coefficient in summer, preventing loss of interior heat in winter and allowing occupants to reduce electric lighting use by making maximum use of daylight, they will have the great potential to dramatically reduce building energy consumption and peak demand in the next generation of massively glazed buildings.