Thin Film Module Technology

Ideal for Converting Sunlight into Electricity

Technologies & Capabilities /  Advanced PV Modules /  First Solar Advanced Thin Film Modules /  CdTe Technology
Our Cadmium Telluride (CdTe) thin film technology is an optimal material for converting sunlight into electricity and is the underlying driver of our module’s performance, cost structure, and bankability.
The semiconductor material used in our thin film modules has the highest theoretical efficiency of any PV material known today, significantly higher than crystalline silicon. Combined with the lowest inherent manufacturing costs, CdTe presents the greatest opportunity for solar electricity to change the way the world is powered.

Theoretical Efficiencies

This curve, known as the S-Q limit, illustrates the thermodynamic efficiency limit for single-junction conversion of the solar spectrum. Our thin film module technology has the highest theoretical efficiency of any other material.


There have been 5 world records in CdTe efficiency over the past 3 years. On the contrary, single crystal and multicrystalline silicon have not achieved a breakthrough in research cell efficiency since 1999 and 2004, respectively; demonstrating that the practical efficiency limit of these technologies has nearly been met.

The gap between First Solar’s top research cell (21.5%) and the theoretical limit (near 30%) of our technology represents tremendous opportunity for improvement. We invest significantly in R&D to uncover the processes and materials required to further increase the efficiency of our thin film module technology. Having recently acquired GE’s technology IP and announced a technology and commercial partnership, our R&D team believes it has a clear line of sight to a 23% efficient thin film PV cell.

Total cost of electricity pricing includes the levelized cost of electricity (LCOE) and economic externalities such as environmental impacts. With the smallest carbon footprint, fastest energy payback time, and lowest life cycle water use, CdTe PV has the lowest externalities of all solar and conventional energy technologies, resulting in the lowest energy price on a total cost basis. By creating more value with less environmental impact per kWh generated, First Solar’s advanced thin-film technology is the leading eco-efficient energy solution.

Mid-Range Total Cost of Electricity

Source: P. Sinha, M. de Wild-Scholten, A. Wade, and C. Breyer, Total Cost of Electricity Pricing of Photovoltaics, presented at EU PVSEC 2013.

In addition to the highest theoretical efficiency and lowest inherent manufacturing costs, our thin film module technology has a superior temperature coefficient and spectral response, resulting in a significant performance advantage compared to conventional crystalline silicon solar modules.

Module High-Heat

Based on actual data, the illustration above compares two systems with identical capacity and weather conditions: a 500kWp First Solar system in the U.S. Desert Southwest and a typical crystalline silicon system with an equal nameplate. Due to the performance advantage of our technology, the First Solar system produced 11.3% more peak power and 9% more energy (kWh) than the crystalline silicon system with the exact same nameplate rating.

On a lifecycle basis, our thin film module technology has the smallest carbon footprint of any other PV technology.

Carbon Footprint

By utilizing a manufacturing process that is less energy-intensive than that of competing solar technologies, our thin film module technology also has the fastest energy payback time in the industry (less than 1 year), reducing the time it takes for a system to generate the amount of energy that was needed to produce it. A fast energy payback time enables PV to scale while achieving faster carbon reductions.

Energy Payback Time

The semiconductor material utilized in our thin film module technology is sustainably sourced from byproducts of the zinc and copper industries. Cadmium, a waste byproduct of zinc refining, and tellurium, a byproduct of copper refining, are converted into a stable CdTe compound. Once encapsulated in First Solar modules, CdTe produces clean, affordable solar energy throughout the modules’ 25+ year lifetime.

Series 4 Thin Film Layers