Ultra-thin van der Waals crystals as semiconductor quantum wells

Control over the electronic spectrum at low energy is at the heart of the functioning of modern advanced electronics which highly relies on meticulous engineering of the size quantization of electrons in quantum wells. This avenue hasn’t yet been explored in 2D materials. Here we transfer this concept onto the van der Waals heterostructures which utilize few-layers films of InSe as quantum wells. Precise control over the energy of the subbands and their uniformity guarantees extremely high quality of the electronic transport in such systems. Using novel tunnelling and light emitting devices, we reveal the full subbands structure by studying resonance features in the tunnelling current, photoabsorption and light emission. [1]

[1] J. Zultak et al, arXiv:1910.04215