Piezoelectric device

A piezoelectric device, comprising:

• a base that includes a first main surface and a second main surface opposed to the first main surface;
• and
• a laminated portion that is laminated on the first main surface of the base;
• wherein
• the laminated portion includes:
• a single crystal piezoelectric layer;
• and
• a pair of electrode layers that apply a voltage to the single crystal piezoelectric layer;
• the single crystal piezoelectric layer includes a first recess in a first opposing surface that opposes the first main surface of the base;
• the single crystal piezoelectric layer is bonded to the first main surface of the base at a portion of the first opposing surface other than the first recess;
• a lower electrode layer defining at least a portion of the pair of electrode layers and extending over a surface of the single crystal piezoelectric layer opposing the base is at least partially located in the first recess;
• a second opposing surface of the lower electrode layer opposing the first main surface of the base has a surface roughness greater than a surface roughness of the first opposing surface of the single crystal piezoelectric layer;
• a plurality of upper electrode layers define at least a portion of the pair of electrode layers;
• the plurality of the upper electrode layers are separated at a distance from each other, and at least a portion of the plurality of upper electrode layers is above the first recess;
• and
• the lower electrode layer is positioned to at least partially oppose the plurality of the upper electrode layers with the single crystal piezoelectric layer interposed between the lower electrode layer and the plurality of upper electrode layers.