Acoustic wave device for asymmetric frequency bands and manufacturing method, charge when compressed, twisted, or distorted, and similarly compress, twist, or distort when a charge is applied

A method comprising:

• providing an acoustic wave device precursor including an intact first piezoelectric layer;
• forming a first piezoelectric layer with a recess by removing a portion of the intact first piezoelectric layer, wherein the recess extends from a top surface of the intact first piezoelectric layer towards a bottom surface of the intact first piezoelectric layer;
• depositing a common second piezoelectric layer covering the entire first piezoelectric layer, such that the common second piezoelectric layer is in contact with an entire top surface of the first piezoelectric layer and exposed surfaces within the recess;
• patterning the common second piezoelectric layer to provide a second piezoelectric layer, wherein:
• the second piezoelectric layer fully covers the recess and does not cover the entire first piezoelectric layer;
• and
• the first piezoelectric layer and the second piezoelectric layer are formed of different piezoelectric materials;
• and
• forming at least one first electrode over the first piezoelectric layer, and at least one second electrode over the second piezoelectric layer and horizontally confined within the recess, wherein the at least one first electrode does not have overlap with the second piezoelectric layer, and no portion of the first piezoelectric layer exists vertically between the second piezoelectric layer and the at least one second electrode.