Tellurium in Photovoltaic Applications: Advantages, Challenges, and Strategic Significance
Abstract:
Tellurium, one of the rarest elements in the Earth‘s crust, has emerged as a critical strategic material in the global photovoltaic industry. Its primary application lies in cadmium telluride thin-film solar cells, which have achieved gigawatt-scale production and now account for approximately 40% of the utility-scale solar market in the United States. This white paper provides a comprehensive analysis of the technical advantages of tellurium-based photovoltaic technologies, the critical challenges—particularly supply chain constraints—and the latest research breakthroughs shaping the industry’s future.
1. Introduction
As the global energy transition accelerates, photovoltaic technologies are being deployed at an unprecedented scale. While crystalline silicon dominates the market, cadmium telluride thin-film photovoltaics have carved out a significant niche, particularly in utility-scale applications. Tellurium, the key constituent of the CdTe absorber layer, has thus gained strategic importance. This white paper examines tellurium‘s role in photovoltaics, integrating the latest market data, research breakthroughs, and policy developments up to April 2026.
2. Tellurium’s Core Application: CdTe Thin-Film Solar Cells
2.1 Material Properties
Cadmium telluride is a II-VI compound semiconductor with a direct bandgap of approximately 1.45 eV, optimally matched to the solar spectrum. Its theoretical conversion efficiency limit approaches 33%. The material‘s high optical absorption coefficient (>10⁵ cm⁻¹) enables effective light absorption with absorber layers as thin as 1-2 μm—approximately two orders of magnitude thinner than crystalline silicon wafers.
2.2 Commercial Status
CdTe photovoltaic modules have achieved gigawatt-scale production, representing approximately 5% of the global solar market and up to 40% of the U.S. utility-scale market-. Manufacturing capacity has grown at an average compound annual growth rate of 37% since 2017-1. First Solar is the dominant global producer, with Chinese firms including Longyan Energy Technology and CTF Solar also active in this space.
3. Key Advantages of CdTe Photovoltaics
3.1 Economic Advantages
| Metric | CdTe Thin-Film | Crystalline Silicon | Source |
| Production Cost | ~$0.15/W | ~$0.20-0.25/W (multi-Si) | Industry data |
| LCOE | $38–$65/MWh | $38–$78/MWh | |
| Manufacturing Temperature | <600°C | >1500°C (crystal growth) | |
| Material Thickness | 1-2 μm | 150-200 μm |
3.2 Performance Advantages
Temperature Coefficient: CdTe modules exhibit a temperature coefficient of approximately -0.26%/°C, superior to crystalline silicon’s -0.35% to -0.40%/°C. This translates to higher energy yield in hot and humid climates, where CdTe modules outperform equivalently rated silicon modules.
Low-Light Performance: As a direct-bandgap material, CdTe demonstrates superior performance under low-light conditions, extending effective generation hours during dawn, dusk, and overcast periods.
No Light-Induced Degradation: CdTe cells do not suffer from the light-induced degradation effects observed in crystalline silicon, maintaining over 80% of rated power output after 25 years.
3.3 Environmental and Sustainability Advantages
Lower Carbon Footprint: The lower processing temperatures and reduced material requirements result in a significantly smaller lifecycle carbon footprint compared to silicon-based photovoltaics.
Closed-Loop Recycling: Established recycling programs achieve recovery rates exceeding 90% for glass, tellurium, and cadmium, addressing both supply concerns and environmental considerations.
4. Critical Challenges
4.1 Tellurium Supply Constraints
The most fundamental challenge facing CdTe photovoltaics is tellurium supply.
By-Product Dependency: Tellurium is recovered almost exclusively as a by-product of copper refining. Its supply is therefore governed by copper production dynamics rather than independent demand signals. Recovery rates from copper ores are declining, exacerbating supply risk and potentially hampering PV deployment.
Supply-Demand Outlook: A 2025 roadmap published in Joule outlines that achieving a manufacturing capacity of 100 GWDC/year by 2030 will require simultaneous improvements in: tellurium extraction efficiency from existing supply chains; absorber layer thickness reduction to minimize material usage per watt; and module efficiency enhancements-1. The roadmap emphasizes that both scientific and supply chain innovations will be necessary to maintain the industry’s high compound annual growth rate.
4.2 Efficiency Gap
While laboratory champion cells have achieved efficiencies exceeding 23%, commercial module efficiencies average approximately 16%—significantly below the theoretical limit of ~33% and current crystalline silicon benchmarks of ~29%.
The primary bottlenecks include: bandgap limitation—the 1.45 eV bandgap prevents effective absorption of photons beyond ~860 nm, resulting in “red loss”; and interface recombination—lattice and band misalignment at the CdTe/CdS interface results in defect densities of ~10¹² cm⁻³ and open-circuit voltage losses exceeding 150 mV.
4.3 Cadmium Toxicity Concerns
Although CdTe compound stability and toxicity are substantially lower than elemental cadmium, regulatory hurdles—particularly under EU RoHS directives—require ongoing engagement and robust recycling infrastructure.
4.4 Competitive Pressures
CdTe faces competition from multiple fronts: crystalline silicon benefits from massive scale economies and continuous cost reduction; CIGS thin-film cells achieve 23.6% laboratory efficiency; perovskite single-junction cells have reached 26.7% and are advancing toward perovskite/silicon tandems.
5. Recent Technological Breakthroughs
5.1 Synergistic Light-Heat-Bias Activation
In December 2025, researchers from Jinan University reported in ACS Energy Letters a “light-heat-bias” synergistic activation strategy that achieved 21.02% efficiency in CdSeTe thin-film solar cells. The strategy involves simultaneous application of illumination, heating, and forward bias, effectively suppressing non-radiative recombination at the front interface and within the absorber layer. The process demonstrates good reversibility and reproducibility across both copper-doped and group-V element-doped devices.
5.2 Interface Passivation
Researchers at the University of Michigan, in collaboration with First Solar, have demonstrated a solid-state cation exchange strategy to passivate the CdTe/ZnTe interface, achieving champion device efficiencies exceeding 23%.
5.3 Tandem Architectures
In March 2026, Xinyi Glass filed a patent for a “CdTe-Perovskite tandem structure” that integrates rigid CdTe cells with flexible perovskite cells in a nine-layer stacked configuration. The tandem structure achieves a 30-40% improvement in power generation efficiency compared to single-junction CdTe cells, targeting building-integrated photovoltaic applications.
6. Market Outlook and Policy Landscape
6.1 Market Size
The global CdTe thin-film solar cell market is projected to reach USD 7.372 billion in 2025 and expand to USD 16.523 billion by 2032, at a CAGR of 12.22%. The overall thin-film photovoltaic market was valued at USD 7.25 billion in 2025 and is forecast to reach USD 26.16 billion by 2034, at a CAGR of 15.32%-.
6.2 Strategic Export Controls
On February 4, 2025, China’s Ministry of Commerce and General Administration of Customs issued Announcement No. 10, implementing export controls on tungsten, tellurium, bismuth, molybdenum, and indium-related items. The controlled list explicitly includes tellurium metal and tellurium compound products including CdTe. This policy underscores tellurium‘s elevation to strategic critical mineral status.
6.3 Pricing Trends
As of February 2026, tellurium traded at 760 yuan/kg, reflecting a 4.11% increase over the preceding month and a 12.59% year-over-year increase. High-purity tellurium (5N) trades at 860-880 yuan/kg, with 6N material reaching 1000-1200 yuan/kg-. Long-term demand growth driven by photovoltaic deployment and CdTe technology expansion is expected to support further price appreciation.
7. Conclusion and Outlook
Tellurium-based CdTe photovoltaics represent a compelling technological pathway for solar energy deployment, particularly in high-temperature climates and utility-scale applications. The technology’s advantages in cost, temperature performance, and carbon footprint position it favorably within the broader PV ecosystem.
However, the fundamental constraint of tellurium supply—stemming from its by-product status and declining recovery rates—represents the most significant barrier to accelerated growth. Addressing this challenge requires coordinated advances across the value chain: improved extraction efficiency from copper refining, reduced material intensity through thinner absorbers, enhanced module efficiencies, and expansion of closed-loop recycling.
Recent breakthroughs in activation strategies, interface passivation, and tandem architectures provide encouraging evidence that the technical roadmap toward higher efficiency is viable. Meanwhile, strategic export controls signal the growing geopolitical significance of tellurium as a critical mineral.
In the context of global decarbonization imperatives and evolving supply chain dynamics, tellurium will remain a focal point at the intersection of materials science, energy policy, and industrial strategy.
