Based on a computer model developed by MIT engineers, it is possible to capture a broad spectrum of sunlight using a very thin film (about 6 Angstroms) of molybdenum disulfide (MoS2) that is poked with a microscopic needle at the center, creating a field of varying (non-uniform) elastic strain, and thus, varying band gap across the film.
Like pressure application, strain engineering can also improve a material’s properties unprecedentedly. The computer model devised by the MIT research engineers simulated the effects of strain produced on a stretched MoS2 film.
The funnel-shaped MoS2 film has varying elastic strains (change in elongation) that are precisely controlled. The strain varies with distance across the film such that it is at its maximum at the center.
Varying strains produce changes in the atomic structure that result to varying potential energy of the electrons, and thus varying band gaps, which allow absorption of different wavelength ranges of light including visible range and some of the invisible light.
The research group’s future work is to test the film in actual experiments. Hopefully, the results would be in accordance to the model.