Amazon-backed Ambient begins mass production of low-light solar cells

26 Apr 2023

Startup has developed dye-sensitized solar cells designed to harvest indoor light for powering small electronic devices.

Ambient Photonics, a photovoltaics startup firm based near Santa Cruz, California, says it has begun mass production of novel solar cells designed to harvest low levels of indoor light.

Supported by Amazon, among others, the company believes that its dye-sensitized solar cells - produced on clear optical glass - will find applications powering small electronic devices, thereby eliminating the need for batteries.

Ambient’s CEO Bates Marshall claimed in a company release: “Day 1 of our factory operations marks a major milestone for the growing Ambient team as we celebrate surpassing our aggressive growth targets and global expansion goals.

“With our new-to-the-world, highly automated production process now online, we are significantly stepping up our impact on cutting carbon emissions from the world's largest device manufacturers.”

Ambient corporate video:

Broad-spectrum absorpion
Armed with nearly $50 million in series A venture finance, raised in part via Amazon’s Climate Pledge Fund and Ecosystem Integrity Fund, Ambient has constructed a 43,000 square-foot manufacturing facility that is said to be capable of producing tens of millions of units per year - and is the first of its kind in the US.

“Ambient’s PV cell technology transforms indoor light into energy with three times more power density than conventional technology and is produced at mass-market price points,” claims the firm.

“Providing endless power for electronic devices, the PV cells eliminate the need for disposable batteries and can reduce the carbon emissions of battery-powered devices by as much as 80 per cent.”

That technology is based on some novel chemistry initially developed at the Warner Babcock Institute for Green Chemistry in Lowell, Massachusetts, with Ambient spun off in 2019 by co-founders Marshall and CTO Kethinni Chittibabu.

Chittibabu was previously principal scientist at the flexible organic PV technology developer Konarka Technologies, which received substantial venture support during the solar boom period of the late-2000s before ceasing operations in 2012.

Ambient says that it has developed more than 40 new organic sensitizer molecules, with absorption peaks across the visible and near-ultraviolet spectral regions. By using a combination of those dyes in its cells, the materials are able to harvest ambient light relatively efficiently.

Industrial printing process
The US National Renewable Energy Laboratory’s latest chart of the best-performing research-level solar cells shows a cell developed at École Polytechnique Fédérale de Lausanne in Switzerland as the most efficient dye-sensitized cell so far, with an efficiency of 14 per cent.

But Ambient claims that its technology offers a performance superior to the amorphous silicon cells typically used for indoor PV applications, even comparing it to high-specification gallium arsenide devices.

Unlike either of those technologies, however, Ambient says its cells can be manufactured using an inexpensive industrial printing process, and applied to thin and durable glass substrates to create cells of virtually any size and shape.

“Unlike expensive semiconductor vacuum manufacturing methodologies, Ambient’s rapid production process is efficient, scalable, and cost-compatible with mass-market electronics manufacturing,” states the firm on its web site.

“In addition, because Ambient cells are customized by device operating environment and industrial design as a matter of course, there is no cost penalty for buying exactly what you need.

“Ambient cells can be manufactured in a variety of custom sizes from 5 cm² to 225 cm², allowing industrial designers to drive photovoltaic cell design, rather than the other way around as is typical with amorphous silicon cells.”

Having already agreed a deal with Universal Electronics, Ambient says it is initially focused on replacing batteries with cells in devices like remote controls, keyboards and mice, electronic shelf labels, and sensors.