Quick answer
Thin-Film Solar Panel A thin-film solar panel is a panel that makes electricity from a light-absorbing layer only a few microns thick, deposited onto glass, metal or plastic, instead of from sliced silicon wafers.
The main types are cadmium telluride (CdTe), CIGS and amorphous silicon. Thin film is about 2% of world production, and in the US its largest use is utility-scale solar farms rather than home roofs.
Quick facts
The key facts about thin-film solar panel, with sources:
- Share of production
- About 2% thin film, 98% crystalline silicon (2025) 1
- CdTe share, 2022
- 21% of the US market and 4% of the global market 5
- Main types
- Cadmium telluride (CdTe), copper indium gallium selenide (CIGS), amorphous silicon (a-Si)
- Layer thickness
- A few micrometres, or millionths of a metre 4
- Example module efficiency
- 18.1%–19.3% (First Solar Series 7 TR1, CdTe) 2
- Example temp. coefficient
- −0.32%/°C (same sheet) 2
- Research cell records
- CdTe 22.6%, CIGS 23.6%, a-Si 12.7% 3
Key takeaways
- Thin film coats a very thin light-catching layer onto a sheet, instead of using sliced silicon wafers.
- The three main types are CdTe, CIGS and amorphous silicon. CdTe is the only one made at large volume.
- It is about 2% of world production and is used mostly on large solar farms.
- Lower efficiency means more area for the same watts, so it rarely suits a normal home roof.
- Flexible thin-film panels fit RVs, boats and curved or weak roofs. Check their warranty closely.
What makes a panel "thin film"
Every solar panel has a layer that soaks up light and frees electrons, the tiny charges that make current. In a normal panel that layer is a silicon wafer about as thick as a few sheets of paper.
In thin film the layer is far thinner. NLR (formerly NREL) says it is only a few micrometres thick, meaning a few millionths of a metre. That works because materials like cadmium telluride soak up light much more strongly than silicon, so less of them is needed.
The DOE calls CdTe the second most common solar technology after crystalline silicon. It made up 21% of the US market and 4% of the global market in 2022.
The three thin-film families
| Type | Light-catching layer | Research-cell record (NLR table) | Where you meet it |
|---|---|---|---|
| CdTe | Cadmium telluride on glass | 22.6% (First Solar, 2024) | Utility-scale farms; the only thin film made at large volume |
| CIGS | Copper indium gallium selenide | 23.6% (Evolar/Uppsala University, 2023) | Flexible and lightweight products, some building-integrated panels |
| Amorphous silicon (a-Si) | Silicon with no crystal pattern | 12.7% stabilised (Sanyo, 1992) | Calculators, small chargers, older flexible RV panels |
Sources: [3]
How it differs from a silicon panel
A silicon cell starts as a wafer sawn from a block, and cells are wired together with thin metal ribbons. Thin film is built the other way round.
The material is coated onto a whole sheet of glass at once. A laser or tool then scribes it into long, narrow strip cells joined end to end.
First Solar’s Series 7 TR1 data sheet lists "thin film CdTe semiconductor, up to 268 cells" on one panel. The DOE says a CdTe module can be made in under 4.5 hours with fast production lines.
Strip cells change how the panel reacts to shade. On a silicon panel, one shaded cell can pull down a whole group. On long thin strips, a shadow across the short side touches every strip a little, instead of a few cells a lot. First Solar lists "shading response" among its selling points.
Example: one utility thin-film panel vs one home silicon panel
| Spec | First Solar Series 7 TR1 (CdTe) | Canadian Solar TOPHiKu6 (TOPCon silicon) |
|---|---|---|
| Module efficiency | 18.1%–19.3% 2 | up to 23.4% 9 |
| Temp. coefficient (Pmax) | −0.32%/°C 2 | −0.29%/°C 9 |
| Warranted yearly degradation | 0.3% 2 | 0.4% after year one 9 |
| Built for | Utility-scale arrays | Home and business roofs |
| Watts per m² at 1,000 W/m² light (our math) | 1,000 × 19.3% = 193 W | 1,000 × 23.4% = 234 W |
What that example tells a homeowner
The silicon panel makes about 41 more watts per square metre at test conditions. On a home roof, where space runs out, that gap decides how big a system fits.
The thin-film panel wins on yearly wear: 0.3% against 0.4%. On a big, open solar farm, where land is cheaper than roof, that kind of trade can make sense. It is one reason CdTe dominates there and not on houses.
Where thin film is used
Large ground-mounted solar farms are the main home of CdTe in the US. You will rarely see rigid CdTe panels on a house.
Flexible and light products are the second use. NLR notes thin film can be flexible and light, which suits portable gear and products like windows that make power. On homes that includes some RV and boat roofs, and some solar shingle and building-integrated products.
Tiny a-Si cells power calculators and small chargers. Older flexible RV panels were often a-Si too.
Where thin film makes sense, and where it does not
Strengths
- Flexible CIGS and a-Si can follow curved surfaces such as RV and boat roofs.
- Low-weight products exist for roofs that cannot carry glass panels.
- Strip cells handle some shade patterns better 2.
- DOE says CdTe making emits much less carbon dioxide than silicon making, and more than 90% of a CdTe panel can be recycled 5.
- Uniform look; some products are built into roofing or glass.
Limits for a home roof
- Lower efficiency means more roof area for the same wattage.
- Few home installers in the US stock rigid thin-film panels.
- Flexible panels laid flat run hot and often carry shorter warranties.
- CdTe contains cadmium, so end-of-life handling matters.
Limits to weigh before choosing thin film
Space is the first limit. You need more square metres for the same watts, and most homes run out of roof first.
Track record is the second. An NREL review of nearly 2,000 measured wear rates found thin film improved a lot after 2000. Older thin-film products wore faster, so be wary of used or very old stock.
Support is the third. Fewer installers and repair shops know thin-film products, which can make later repairs harder.
Sources: [6]
What drives the cost of thin film
HyreSolar does not publish panel prices. For a home, the main driver is area. Lower efficiency means more panels, more racking and more labor for the same kW. Our cost per watt guide shows how to compare quotes on an equal basis.
Specialty products cost differently. Flexible panels for RVs and lightweight roofs are a separate market with their own pricing and warranties.
End of life is part of cost too. DOE says recycling routes exist for CdTe but that US recycling generally costs more than landfill today.
How a thin-film system is installed
A licensed installer and electrician do the work. Rigid panels follow the same steps as silicon ones.
- The installer checks the roof or site, shade and the structure’s load limit.
- They confirm the panel is listed for your use and that racking or adhesive is approved for it.
- They draw plans and apply for a building and electrical permit.
- They apply to the utility to connect, a step called interconnection.
- Crews mount the panels and run wiring to the inverter or, off grid, to a charge controller.
- An inspector checks the work. The utility then gives permission to operate.
Caring for thin-film panels
Rigid thin-film panels need the same light care as silicon: watch monitoring and keep heavy dirt off. Our cleaning guide covers safe methods.
Flexible panels need more checks. Look for lifting edges, creases and worn adhesive, especially on vehicles that flex and shake.
Do not walk on or bend a flexible panel past the limit on its data sheet.
Warning signs and when to call a pro
Call a licensed installer or electrician for any of these. Do not cut, drill or open a panel.
- Cracked or broken glass on a CdTe panel.
- Peeling, bubbling or creased film on a flexible panel.
- Output that drops sharply in a short time.
- Corrosion around the edges or the connector.
- Water getting under a building-integrated product.
Handling broken CdTe panels
Do not break up or bin a damaged CdTe panel yourself. Have the installer remove it and send it to a recycler.
Standards and rules that apply
Product listing. UL says the NEC, IBC and IRC require PV products on or near buildings to be certified by a Nationally Recognized Testing Laboratory. Panel safety testing is UL 61730-1 and -2, harmonized with IEC 61730.
Roofing products. Thin film built into a roof covering is building-integrated PV. UL says the 2021 IBC and IRC require BIPV roofing to be listed to UL 7103.
Disposal. Waste rules for panels vary by state. DOE’s end-of-life page covers the federal picture; ask your installer how the panels will be handled.
Thin film vs silicon panel types
| Thin film (CdTe) | Monocrystalline | Polycrystalline | |
|---|---|---|---|
| Light-catching layer | A few micrometres of CdTe 4 | Sliced single-crystal silicon wafer | Sliced cast silicon wafer |
| Example efficiency | 18.1%–19.3% 2 | Up to 23.4% (TOPCon example) 9 | 16.89%–17.39% (2018 sheet) |
| Main use | Utility farms; flexible niche products | Homes, businesses, farms | Older systems |
| Share of production | About 2% for all thin film 1 | All silicon wafers in 2025 1 | Largely gone |
Misconceptions
- Myth Thin film always beats silicon in heat.
- Reality Not on the sheets here. The CdTe panel lists −0.32%/°C and the TOPCon silicon panel −0.29%/°C 2 9. Compare the actual numbers.
- Myth All flexible panels are thin film.
- Reality Some flexible panels use thin crystalline silicon cells sealed in plastic. The cell-type line on the data sheet tells you which.
- Myth Thin film is outdated.
- Reality CdTe is a major utility product and holds a 22.6% research-cell record 3. It is rare on homes, not obsolete.
- Myth Cadmium makes the panels unsafe to live near.
- Reality The cadmium compound is sealed between glass sheets. The concern is breakage and disposal, which is why recycling routes matter 5.
Thin film in SC, GA and VA
No state rule in SC, GA or VA picks panel technology. The same permits, utility rules and size caps apply. Georgia Power limits residential renewable systems to 10 kW, so a lower-efficiency panel uses more roof for the same allowed size 11.
Virginia allows residential net metering up to 25 kW on investor-owned utilities 12. In South Carolina, SC LLR registers solar panel installers as a residential specialty; confirm yours is registered before any specialty install 10.
Is thin film right for you?
Thin film is worth a look when one of these is true:
- The surface is curved, such as an RV, van or boat roof.
- The roof cannot carry the weight of glass panels; see panel weight and roof loading.
- You want power built into a roofing or glass product.
- You have plenty of space and want a product with low yearly wear.
- For a normal roof, compare mono silicon quotes first; most homes fit more power that way.
Next steps
Questions about thin-film solar panel
Are thin-film solar panels good for homes?
Usually not for a standard roof. Their lower efficiency needs more space, and few home installers carry them. They fit special cases: curved or very light structures, RVs and boats, and some building-integrated products. For a normal roof, mono silicon panels usually fit more power.
What is the most efficient thin-film technology?
CIGS holds the top research-cell record at 23.6%, with CdTe at 22.6%, in the NLR (formerly NREL) table. Those are small lab cells. The best commercial CdTe panel cited here, the First Solar Series 7 TR1, reaches 19.3%.
Do thin-film panels work better in heat?
Not automatically. The First Solar Series 7 TR1 loses 0.32% of power per degree of heat, while a current TOPCon silicon panel loses 0.29%. Older a-Si panels did handle heat well in some studies. Always compare the coefficients on the data sheets you are quoted.
Are flexible solar panels thin film?
Many are CIGS or amorphous silicon, but not all. Some flexible panels use thin crystalline silicon cells sealed in plastic. The cell-type line on the data sheet tells you which. Either way, check how hot the panel runs when laid flat and how long the warranty lasts.
How long do thin-film solar panels last?
Modern rigid CdTe panels are built for long service. First Solar warrants 0.3% yearly loss on its Series 7 TR1. An NREL review found thin-film wear rates fell sharply for panels installed after 2000. Flexible products often carry shorter warranties, so read yours.
Is cadmium in solar panels dangerous?
The cadmium compound in CdTe panels is sealed between sheets of glass. The concern is broken panels and disposal. DOE says more than 90% of a CdTe panel can be recycled. Have a pro remove broken panels and send them to a recycler.
What is the difference between thin film and monocrystalline?
Thin film coats a layer a few micrometres thick onto glass or plastic. Monocrystalline panels use sliced wafers of single-crystal silicon. Mono is more efficient and dominates home roofs. Thin film, mainly CdTe, is used on large solar farms and in flexible products.
Who makes thin-film solar panels?
First Solar is the best-known maker of CdTe panels, and its Series 7 is built for utility-scale arrays. CIGS and a-Si are made by smaller firms, often for flexible or specialty products. Ask your installer for the data sheet of any thin-film product you are offered.
Can thin-film panels be recycled?
Yes. DOE says recycling processes exist for CdTe panels and that more than 90% of a CdTe panel can be recycled. It also notes US recycling generally costs more than landfill today. Ask the maker or installer about take-back programs before you buy.
Sources
- VDMA, International Technology Roadmap for Photovoltaic (ITRPV), 17th Edition, Results 2025 (June 2026), retrieved .
- First Solar, Series 7 TR1 US module data sheet MPD-00640-07-US (April 2026), retrieved .
- National Laboratory of the Rockies (formerly NREL), Best Research-Cell Efficiency data table, retrieved .
- National Laboratory of the Rockies (formerly NREL), Solar Photovoltaic Technology Basics, retrieved .
- US DOE Solar Energy Technologies Office, Cadmium Telluride, retrieved .
- Jordan and Kurtz, NREL, Photovoltaic Degradation Rates — An Analytical Review (NREL/JA-5200-51664, 2012), retrieved .
- US DOE Solar Energy Technologies Office, End-of-Life Management for Solar Photovoltaics, retrieved .
- UL Solutions, Building-Integrated Photovoltaic (BIPV) System Testing and Certification (UL 7103, UL 61730), retrieved .
- Canadian Solar, TOPHiKu6 CS6.2-54TM data sheet V1.2_EN (March 2025), retrieved .
- SC LLR, Residential Specialty Contractor registration (Solar Panel Installer), retrieved .
- Georgia Power, Behind-the-Meter Interconnection Summary for Residential Customers (rev. 15 Aug 2025), retrieved .
- Code of Virginia §56-594 (net energy metering), retrieved .
Expert review
Written by the HyreSolar Research team. Not yet reviewed by an outside expert. We say so rather than imply a review that has not happened; see our editorial policy.
How the numbers were checked: Market share from ITRPV 17th Edition and DOE SETO; records are the highest value per thin-film category in the NLR data table; module specs read from the named data sheets; wear-rate history from the NREL review by Jordan and Kurtz. Watts-per-square-metre rows are our arithmetic on data-sheet efficiency.
Suggest a correction. We fix errors and say what changed.