Strain-engineered inverse charge-funnelling in layered semiconductors

Abstract

The control of charges in a circuit due to an external electric field is ubiquitous to the exchange, storage and manipulation of information in a wide range of applications. Conversely, the ability to grow clean interfaces between materials has been a stepping stone for engineering built-in electric fields largely exploited in modern photovoltaics and opto-electronics. The emergence of atomically thin semiconductors is now enabling new ways to attain electric fields and unveil novel charge transport mechanisms. Here, we report the first direct electrical observation of the inverse charge-funnel effect enabled by deterministic and spatially resolved strain-induced electric fields in a thin sheet of HfS2. We demonstrate that charges driven by these spatially varying electric fields in the channel of a phototransistor lead to a 350% enhancement in the responsivity. These findings could enable the informed design of highly efficient photovoltaic cells.

Toward Air Stability of Thin GaSe Devices: Avoiding Environmental and Laser‐Induced Degradation by Encapsulation

“…This process can introduce strain in the atomic lattice thus modifying the optical and electronic properties of GaSe. [9g,20] A second observation is that the number of bubbles increases in time as shown by the bottom panel of Figure d. The initial formation and growth of an individual bubble is shown in Figure e by the cross section of the AFM images taken in the region highlighted by the arrows in panel (c).…”

“…Moreover, the presence of these materials can perturb the GaSe lattice and introduce strain, which may change the photoresponse. [9g,20]…”

Tunable Photodetectors via In Situ Thermal Conversion of TiS3 to TiO2

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ReS2 Charge Trapping Synaptic Device for Face Recognition Application

“…However, ReS 2 within ten layers are all considered to have a direct bandgap [11], which means ReS 2 within ten layers can all perform well. Besides, the asymmetric lattice structure leads to weaker interlayer coupling energy, which benefits the exfoliation work, and thus makes the synaptic device much easier to fabricate [12][13][14][15]. In this study, ReS 2 film is used as a channel material.…”