Direct evaporation of single-crystal metal contacts for 2D semiconductors.

August 27, 2026| Source: Science (New York, N.Y.)

Metal contacts remain one of the key bottlenecks in two-dimensional (2D) semiconductor electronics. We developed an atomic-scale step-by-step evaporation method to directly grow single-crystal metals on monolayer semiconductors with clean interfaces. This method accesses a distinct growth-kinetic window that suppresses secondary nucleation and promotes lateral coalescence, enabling van der Waals epitaxy of diverse metals-including bismuth, silver, indium, gold, and palladium-on molybdenum disulfide (MoS 2 ) and tungsten diselenide (WSe 2 ). The single-crystal metals support ultrathin conduction, provide spatially uniform work functions, and exhibit improved thermal robustness. As contacts, they show minimal Fermi-level pinning, approaching the Schottky-Mott limit. With bismuth and palladium contacts, monolayer MoS 2 and WSe 2 transistors achieved ultralow n- and p-type contact resistances of 36 and 145 ohm-micrometers, respectively, and short-channel currents both above 1.1 milliampere per micrometer.

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Indirect reciprocity with dual private assessment.

People often cooperate out of concern for their reputation. The corresponding theory of indirect reciprocity predicts that such cooperation can only evolve if people's opinions of each other are sufficiently correlated. This correlation, however, can be difficult to achieve when individuals form their opinions independently from one another, as in private assessment models. In that case, errors can generate disagreements that propagate throughout a population. Here, we identify a simple mechanis

Physical/TechSeptember 26, 2026

A genetic program for rapid initiation of axillary meristems at the onset of flowering.

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Physical/TechSeptember 26, 2026

David Botstein: A pioneering geneticist and educator 1942-2026.

David Botstein, who died on February 27, 2026, was a towering figure in the field of modern molecular genetics. His research career was largely focused on the development of methods to better understand biological systems, beginning with his early work on Salmonella phage P22 and yeast, where he exploited the use of conditional lethal mutations as suppressors to identify genes with common functions and to order them in a pathway. He is best remembered for developing restriction fragment length p

Physical/TechSeptember 26, 2026

Ultra-narrowband organic room-temperature phosphorescence achieved by boosting low-frequency vibronic coupling.

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Physical/TechSeptember 25, 2026

Multidomain interaction governs the filamentous assembly of the dominant-negative DNMT3A R882H mutant.

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