Researchers at the University of California Los Angeles announced on Mar. 19 a new technique that significantly improves how electrical current enters perovskite semiconductors, which are considered promising materials for next-generation electronics.
The breakthrough addresses a longstanding challenge in the field: the inefficient transfer of electrical current from metal electrodes into perovskite semiconductors. This inefficiency has been compared to a clogged doorway, resulting in wasted energy and slower device performance.
The UCLA team developed a strategy that modifies only a very thin region under the metal contact, allowing electrons to pass through more easily using quantum tunneling. This approach reduces resistance by shrinking the blocked region from about 250 nanometers to less than 25 nanometers, enabling current to flow more efficiently at lower voltages. The research could lead to faster, lower-power, and more reliable perovskite electronic devices.
Perovskites are known for their efficiency and low manufacturing costs and have potential applications in solar cells, sensors, photodetectors, and advanced electronics. However, poor electrical contact between metal electrodes and perovskite semiconductors has limited their use in electronic devices. Traditional methods like impurity doping are difficult with perovskites due to their soft and chemically sensitive nature. The UCLA researchers addressed this by engineering the tiny region directly beneath the metal electrode using silver oxide nanoclusters formed at the interface.
The process involved placing a van der Waals–laminated metal electrode on the perovskite surface, mild thermal annealing to allow silver diffusion into the near-surface region, and ultraviolet light exposure to convert silver into silver oxide nanoclusters. These clusters act as electron acceptors, creating a locally p-doped region beneath the contact and narrowing the energy barrier for charge carriers via Fowler–Nordheim quantum tunneling.
The study’s corresponding author is Xiangfeng Duan of UCLA College; first authors are Boxuan Zhou and Laiyuan Wan. Other contributors include several UCLA-based researchers such as Yu Huang of UCLA Samueli School of Engineering. The findings were published in Nature Materials with support from the National Science Foundation.
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While this work is currently at proof-of-concept stage in laboratories, it demonstrates a promising route for turning perovskites into practical electronic technologies. The concept may also inspire new approaches for other emerging semiconductor materials.
