Mesoporous Semiconductive Bi<sub>2</sub>Se<sub>3</sub> Films
Tomota Nagaura, Aditya Ashok, Azhar Alowasheeir, Arya Vasanth, Minsu Han, Yusuke Yamauchi
Abstract
Bi 2 Se 3 is a semiconductive material possessing a bandgap of 0.3 eV, and its unique band structure has paved the way for diverse applications. Herein, we demonstrate a robust platform for synthesizing mesoporous Bi 2 Se 3 films with uniform pore sizes via electrodeposition. Block copolymer micelles act as soft templates in the electrolyte to create a 3D porous nanoarchitecture. By controlling the length of the block copolymer, the pore size is adjusted to 9 and 17 nm precisely. The nonporous Bi 2 Se 3 film exhibits a tunneling current in a vertical direction of 52.0 nA, but upon introducing porosity (9 nm pores), the tunneling current increases significantly to 684.6 nA, suggesting that the conductivity of Bi 2 Se 3 films is dependent on the pore structure and surface area. The abundant porous architecture exposes a larger surface area of Bi 2 Se 3 to the surrounding air within the same volume, thereby augmenting its metallic properties.