High‐Performance Piezoelectric Nanogenerators Based on Wurtzite BeO Nanowire Arrays

ABSTRACT Wurtzite structured materials have been widely studied for piezoelectric nanogenerators (PENGs) due to their effective piezoelectric response. Among them, beryllium oxide (BeO) has high thermal conductivity (∼370 W/m·K at 300 K) and chemical stability makes it a promising candidate. However, the potential of BeO has been underexplored owing to the challenges in its nanoscale synthesis. In this study, we experimentally demonstrate for the first time the piezoelectric properties of BeO nanowires (NWs) and films. BeO NW arrays were synthesized via atomic layer deposition within anodic aluminum oxide templates. Structural and compositional analyses confirmed BeO NW formation, and piezoresponse force microscopy revealed an effective piezoelectric response with a longitudinal piezoelectric constant ( d 33 ) of 15.8 pm/V for NW, compared to 4.8 pm/V for thin films. Additionally, the BeO NW‐based PENG achieved a maximum output voltage of ∼26.1 V and a maximum power density of ∼0.32 µW/cm 2 , which significantly exceed those of thin films (∼12.0 V and ∼0.09 µW/cm 2 , respectively) and are comparable to those of conventional wurtzite material‐based systems. These findings establish BeO as an experimentally validated wurtzite‐type piezoelectric material and demonstrate its potential for energy harvesting, self‐powered sensors, and reliable operation in harsh environments where thermal and chemical stability are essential.