Here si a very good and detailed report by TaiyangNews on PERC solar cell technolygy that is free fo charge to doenload. Thnak you Roger Görtzen at SoLayTec for letting me know about this one. It shows a slow and steady growth for ALD Al2O3 back side passivisation the next 10 years. One of the major concerns for Al2O3 introduction u either PECVD or ALD is the cost of TMA. For ALD the industry seem to worry about that it is a new technoloogy and that you anyway need too cap of the Al2O3 with a silicon based dielectric PECVD process step.
PERC Solar Cell Technology 2016 – Background, Status and Outlook provides an overview on background, status and outlook of promising high-efficiency silicon-based PERC cell technology.
All solar cell manufacturers that are evaluating capacity expansion
in the current investment cycle have to decide if they stick to
traditional technology or opt for advanced solutions. The simplest and
most attractive silicon cell technology upgrade is called PERC, which stands for Passivated Emitter Rear Cell.
Our new report PERC Solar Cell Technology 2016 – Background, Status and Outlook provides an overview on background, status and outlook of PERC cell technology.
PERC is an advanced silicon cell architecture that comes with a promise of higher efficiencies.
At the same time, it requires only minimal changes to existing solar
cell processing lines. The concept is not new, it was invented in 1983
by well known Australian scientist Martin Green.
Opting for PERC means to add a rear passivation scheme to standard
BSF cell technology. As for the implementation, it involves depositing a
rear surface passivation film, which is subsequently opened to give way
for formation of a rear contact. In addition, the chemical wet-bench
based edge-isolation step is tweaked for rear polishing. The key aspect of PERC technology is to deposit the rear passivation film.
Our study provides background on the different rear passivation materials – the early silicon oxynitride and today state-of-the-art material, aluminum oxide.
The deposition of aluminum oxide can be accomplished by 4 well known
deposition technologies that have been tweaked to apply this dielectric.
While sputtering tools are currently not being offered for commercial
production, there is little demand for APCVD. The two technologies for
aluminum deposition mainly considered by commercial cell producers are
PECVD and ALD. The study shows the pros and cons for each of these deposition technologies.
The report also delves into product details; nearly every
deposition tool supplier is offering a package line for PERC. Short
product descriptions are given on p. 29.
While the the first part of the study deals with equipment and material of PERC cells, we have also looked at the efficiencies and the performance potential at commercial scale. As new record efficiencies are quickly changing for PERC, commercialization of the technology is in full swing.
We estimate that 4.9 GW of PERC capacity was installed in 2015, resulting in about 3 GW of PERC cell production. The report also provides an estimate for 2016 PERC production.
Like any other technology, PERC faces challenges.
The major concern is the so-called Light Induced Degradation (LID)
effect, which, however, is especially associated with multicrystalline
PERC cells today, but some companies already have this issue under
control. In comparison, we also take a brief look at other high-efficiency cell concepts.
However, our overall impression is: PERC seems to be absolutely ready for prime time.
The Report can be downloaded free of charge here.