Nanotechnology

[FreeGrass]

The Next Gen PV Cell Is Smaller than Small

A nanocrystal cell could see all high-rise windows double up as photovoltaic panels.

A surge in innovative design to capture sunlight could see the cost of photovoltaics (PVs) plummet as their applications soar.

The inventor of a nanocrystal cell that could see “the glass of all high-rises in New York” become electricity-generating panels has been awarded the €800,000 Millennium Technology prize. Professor Michael Grätzel of the Lausanne Federal Technology Institute and creator of the dye-sensitised, ultra-efficient Grätzel cell, took inspiration from natural photosynthesis to develop films in which the PV particles “are so small, they don’t scatter light”. His microscopic suntraps are capable of collecting light from all angles, and could be incorporated into window panes, assigning heavy roof-top panels to the past.

Small is beautiful for researchers at Sandia National Laboratories, New Mexico. By producing PV cells no bigger than glitter, they claim to have opened up the door to electricity-generating coatings for almost any shape or surface. The tiny cells are made from crystalline silicon and can be produced cheaply using techniques common to today’s electronics industry.

Researcher Murat Okanda claims that the micro-cells match the efficiency of current PVs, with the added bonus of “a significant reduction in manufacturing and installation cost compared with (standard) techniques”.

Glitter-sized or paper-thin? Scientists at the Solar Frontiers Research Center at the Massachusetts Institute of Technology say they have managed to print solar cells on sheets of paper. Carbon-based dyes act as semiconductors that can convert sunlight into electricity. As yet, the paper cells are far less efficient than current PV cells, but their relatively low cost could make them an attractive option.