Back-contact (BC) solar cells are expected to draw level and reach cost parity with tunnel oxide passivated contact (TOPCon) cells before the end of the decade, according to analysis from pv magazine Week Europe 2025.
During a session on solar and cell module technology held as part of pv magazine’s live broadcast-virtual conference, industry experts discussed the next steps for PV technology, including BC cells, perovskites and tandem cell products.
Molly Morgan, senior research analyst at CRU, told attendees that based on CRU’s internal efficiency forecast and cost modelling forecast, BC technology needs to sustain an efficiency lead of around 1.2% or 1.3% on average over TOPCon to achieve cost per Watt parity.
“We do believe that BC will draw level and reach cost parity with TOPCon before the end of the decade,” Morgan said. “That’s why we believe we might see a coexistence of the two technologies in the 2028 to 2030 timeframe.”
Image: CRU
TOPCon continues to dominate the market, largely due to low manufacturing costs. Morgan said that with TOPCon providing good efficiency metrics, it is natural that some manufacturers are holding back on making the jump to BC, but added that a lot of manufacturers are still demonstrating BC pilot lines and BC modules at their booths at trade shows and conferences.
“Although they’re not producing their own BC sales and modules commercially yet, they have begun to lay the groundwork and to be ready to pounce and initiate a transition away from standard TOPCon to a BC TOPCon design when the market conditions are less challenging, which is what we see to happen in that sort of 2028 earliest time frame,” Morgan explained.
CRU’s forecast adds that heterojunction cells may struggle to gain a meaningful market share away from TOPCon due to higher manufacturing costs, unless the technology can establish a meaningful efficiency lead over TOPCon. “The efficiency lead that we believe would be necessary for that is one that we don’t believe to be likely to be established as the technology category as a whole on average,” Morgan added.
From 2030 and beyond, CRU’s analysis expects tandem technologies to gain momentum on a large scale. “This is driven by the market’s strive for higher efficiencies that can only be unlocked by tandem devices,” Morgan explained.
Perovskite silicon tandems offer the potential to unlock higher efficiency potential, with reports already of 30% efficiencies at the module level. Ed Crossland, chief technology officer at Oxford PV, told attendees the company sees the ceiling for tandem perovskite silicon technology to be 35% plus at the module level.
“Our current product is a 25% module-level product and now demonstrating 2% field-level degradation. In 2027, we’ll see 27% of the module level with 1% or lower degradation levels in the field,” he added. “And I think that’s the really exciting level where we see a full obvious choice for perovskite silicon tandem in many more deployment scenarios than are currently the case.”
Radovan Kopecek, director of ISC Konstanz, added that while he expects BC to be driving the energy transition, tandem technology’s time will also come.
“If you look at Molly’s graph and understand what the production will be at that time, we are talking about 2 TW, 3 TW production,” he said. “I don’t think that tandem until that time will become so bankable that everybody will roll out the technology towards TW. Of course, there will be multiple GW, that’s for sure.”
Kopecek added that three-terminal tandems could also be one of the future solutions.
“I think Oxford PV could also switch very quickly to that if, let’s say, the integration of the cells will be solved. And we have some patent applications on that to interconnect BC devices with perovskite directly on the silicon,” he added. “The development will show, is it a two-terminal, three-terminal, four-terminal, that it will come. It’s clear because then we can really go above efficiencies of 30%.”
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.
Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.
You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.
Further information on data privacy can be found in our Data Protection Policy.