Piezo-response in two-dimensional α-Tellurene films

Monoelemental two-dimensional (2D) materials have attracted significant attention due to their exciting electro-mechanical properties and extreme thinness. However, most of these stable centro-symmetric structures same electronegativities all atoms lack interesting such as piezoelectricity ferroelectricity. Here we report the existence in atomically thin monoelemental α-Tellurium films. DFT calculations reveal that few layer α-Tellurene is electrostrictive. group theory analysis shows belongs piezoelectric C2 negligible asymmetry has high anomalous Born effective charges, similar traditional perovskite structures. Experimental exploration demonstrates through thickness piezoelectricity. With single dual AC resonance tracking force microscopy, coefficient (d33) up 1 pm/V observed for Te ultrathin Moderate dependent α-Te films makes it a promising candidate realization devices.