IIT Bhubaneswar Designs High-Efficiency Tandem Solar Cell Using TMD

In a breakthrough that could advance next-generation solar technologies, researchers at the Indian Institute of Technology (IIT) Bhubaneswar have proposed a new tandem solar cell architecture combining perovskite and transition metal dichalcogenide (TMD) materials. Simulations show the device could potentially achieve a power conversion efficiency exceeding 35 percent.

The novel cell design features a perovskite-based top layer paired with a bottom layer made of molybdenum ditelluride (MoTe₂), a type of TMD known for its excellent semiconducting and optical properties. TMDs are emerging as promising materials for lightweight, semi-transparent, and flexible solar applications, ideal for sectors such as aerospace, electric mobility, wearables, and building-integrated photovoltaics.

“The bandgap tuneability and superior optical features of both perovskites and TMDs make them an ideal combination for two-terminal tandem solar cells,” the researchers said in their paper, published in Results in Optics.

The team used the SCAPS-1D solar simulation software, developed by the University of Ghent, to analyze performance parameters under standard test conditions. Their proposed bottom cell comprises a zinc oxide electron transport layer (ETL), a MoTe₂ absorber, a copper(II) telluride (CuTe) hole transport layer (HTL), and a gold contact. The perovskite top cell features a 1.5 eV bandgap and includes layers of fluorine-doped tin oxide (FTO), titanium dioxide (TiO₂) as the ETL, the perovskite absorber, copper oxide (CuO) as the HTL, and a gold back contact.

Layer thickness optimization and band alignment enhancements were key to achieving simulated results. The top perovskite cell showed an efficiency of 26.2 percent, while the MoTe₂-based bottom cell reached 30.3 percent. When integrated as a tandem structure, the device demonstrated a predicted efficiency of 35.3 percent, with an open-circuit voltage of 2.4 V, a short-circuit current density of 16.3 mA/cm², and a fill factor of 90.3 percent.

“These high simulated efficiencies suggest that tandem architectures using perovskite and TMD absorbers merit experimental investigation,” the authors concluded, adding that such devices could be scalable via roll-to-roll manufacturing techniques for flexible substrates.

If validated in real-world conditions, the technology could open up new avenues in high-efficiency, next-gen solar modules with broad application potential across industries.