Chris Eberspacher, a recognized expert in thin film technology and one of the higher-level technical executives at Nanosolar, has left the company.
Eberspacher had been serving as chief scientist for the company, and before that he was the vice president of research and development.
An analyst termed the departure "significant" because of the technical complexities involved in manufacturing, although Nanosolar CEO Martin Roscheisen said the departure does not impact the company. Nanosolar hopes to produce copper-indium-gallium-selenide (CIGS) solar cells by printing the active CIGS material onto thin foils or other substrates. Eberspacher is an expert in this field. He holds patents and has published patents on printing CIGS.
Prior to working at Nanosolar, he was a co-founder of Unisun and before that, Eberspacher headed up research and development at Arco Solar, which is now owned by Shell.
Like most other CIGS companies, Nanosolar doesn't commercially produce products yet, but hopes to start in 2008. Most of the competitors use a somewhat similar chemical formula for CIGS: the challenge comes in mass manufacturing.
CIGS companies will overcome these challenges, but it will take time and it's unclear at this point which process will work best, wrote Rommel Noufi, a researcher at the National Renewable Energy Lab, in an e-mail. (Noufi wrote the email in response to a question about CIGS in general a few weeks ago and not in response to Eberspacher's departure.)
"There are as many ways to deposit CIGS as there are industries. Some will overcome, and some will fail. Unlike silicon, where everyone almost makes the wafers the same way, in the CIGS case, each industry has to build its own equipment to match their process," Noufi wrote.
Nanosolar will print its CIGS cells. Others will sputter the material onto substrates. Miasole and DayStar, two other CIGS companies, have recently experienced delays.
Nanosolar's Roscheisen, who confirmed the departure, said that Eberspacher over the last 18 months had largely been shifted out of day-to-day management. Meanwhile, Nanosolar has moved from conducting basic scientific research toward manufacturing. Thus, Eberspacher's role as scientist and researcher has become less central to the company's current objectives.
"Chris decided to leave, basically realizing that we now have a ton of really talented and passionate engineers on our team who know their respective areas so well that there's really not much for Chris to contribute," Roscheisen wrote in an email. "We remain on friendly terms with Chris and appreciate his pioneering a lot of the early science in CIGS."
Roscheisen added that the products and processes Nanosolar is currently relying on do not rely on Eberspacher's work.
When he came to Nanosolar in 2004, however, the company trumpeted the hire.
"Chris could have joined any solar company; the fact that he chose Nanosolar is a great validation of the company's team and technology," said Bill Gurley of Benchmark Capital in a press release issued by Nanosolar. (Benchmark is an investor.)
Sources say that more executive changes elsewhere in the CIGS world are afoot as well.